NDA General Ability Test 17 Nov 2019 Official Paper (Previous Year Paper)

The correct answer is 'worried'.

Key Points:- 

• Anxious means feeling or showing worry, nervousness, or unease about something.
• Example: My mother always gets a bit anxious if we don't arrive when we say we will.
• Worried means anxious or troubled about actual or potential problems. 
• Example: They don't seem particularly worried about the situation.
• Therefore, the option that is nearest in meaning to the underlined word 'anxious' is 'worried'.
• Hence, option 1 is the correct answer.

​

Additional Information

• Let us explore the other given options:
• Dispassionate means calm and reasonable, and not affected by emotions.
• Sluggish means slow-moving or inactive.
• Torpid means mentally or physically inactive; lethargic.

Hinglish

• 'Anxious' मतलब किसी बात को लेकर चिंता, घबराहट या बेचैनी महसूस करना या दिखाना।
• उदाहरण: My mother always gets a bit anxious if we don't arrive when we say we will.
• 'Worried' मतलब वास्तविक या संभावित समस्याओं के बारे में चिंतित या परेशान।
• उदाहरण: They don't seem particularly worried about the situation.
• अत: रेखांकित शब्द 'anxious' के अर्थ में निकटतम विकल्प 'worried' है।
• अतः विकल्प 1 सही उत्तर है।
• 'Dispassionate' मतलब शांत और उचित, और भावनाओं से प्रभावित नहीं।
• 'Sluggish' मतलब धीमी गति से चलने वाला या निष्क्रिय।
• 'Torpid' मतलब मानसिक या शारीरिक रूप से निष्क्रिय; सुस्त।

The correct answer is "rapturous" 

Key Points

• Look at the meaning of the given word in the question**:**
• Ecstatic- feeling or expressing overwhelming happiness or joyful excitement.
• Look at the meaning of the selected word:
• Rapturous- means characterized by, feeling, or expressing great pleasure or enthusiasm.
• Look at the meaning of the rest of the options:
• Efficacious- successful in producing a desired or intended result; effective.
• Eerie- strange and frightening.
• Reverential- full of respect and admiration.
• The option that is nearest in meaning to the underlined word ' ecstatic' is 'rapturous'.
• Look at the following example:
• The singer was greeted with rapturous applause.

Hence, the correct answer is Option 3 i.e. rapturous.

Hinglish

• Ecstatic- बहुत ही ज्यादा खुश
• Efficacious- किसी कार्य को करने में सफल होना
• Eerie- अजीब
• Reverential- इज़्ज़त से भरपूर

Option 4 is the right answer.

Seclusion means the state of being private and away from other people.

Nature means the basic or inherent features, character, or qualities of something.

Scripture means writings that are regarded as holy in a particular religion.

Seafaring means the practice of regularly travelling by sea.

Solitariness means a person who lives alone or in solitude.

The option that is nearest in meaning to the underlined word 'seclusion' is solitariness'.

Example - Prince Kaybee has chosen to use the time to enjoy solitariness.

Option 2 is the right answer.

Despot means a ruler or other person who holds absolute power, typically one who exercises it in a cruel or oppressive way.

Conservative means a person who is averse to change and holds traditional values.

Dictator means a ruler with total power over a country, typically one who has obtained control by force.

Passionate means having, showing, or caused by strong feelings or beliefs.

Monstrous means inhumanly or outrageously evil or wrong.

The option that is nearest in meaning to the underlined word 'despot' is 'dictator'.

Example - Hitler was a dictator.

The correct answer is "lively".

Key Points

• Look at the meaning of the word in the question:
• Vivid means intensely deep or bright.
• Look at the meaning of the selected word:
• Lively means full of life and energy; active and outgoing.
• Inert- lacking the ability or strength to move.
• Ebullient- cheerful and full of energy.
• Caustic- sarcastic in a scathing and bitter way.
• The option that is nearest in meaning to the underlined word 'vivid' is ' lively'.
• Look at the following example:
• There was some lively discussion at the meeting.

Hence, the correct sentence: The imagery used in the poem is lively.

Hinglish

• Lively- जोश से भरपूर
• Inert- जिसके पास एनर्जी न हो, जिसको दुषरे से कोई मतलब न हो
• Ebullient- ऊर्जा से भरपूर
• Caustic- व्यंग्यपूर्ण

Option 3 is the right answer.

Vulnerable means exposed to the possibility of being attacked or harmed, either physically or emotionally.

Resilient means able to withstand or recover quickly from difficult conditions.

Elastic means able to resume its normal shape spontaneously after being stretched or compressed.

Defenceless means without defence or protection; totally vulnerable.

Crude means in a natural or raw state; not yet processed or refined.

The option that is nearest in meaning to the underlined word 'vulnerable' is 'defenceless'.

Example - He punched the doorman to the ground from behind before kicking the man to the head as he lay defenceless on the ground.

Option 4 is the right answer.

Key Points 

• Vitriolic means filled with bitter criticism or malice. (कड़वी आलोचना या द्वेष से भरा हुआ)
• Imaginative means having or showing creativity or inventiveness. (रचनात्मकता या आविष्कारशीलता होना या दिखाना)
• Sprightly means lively; full of energy. (जीवंत; ऊर्जा से भरा हुआ)
• Vivacious means attractively lively and animated. (आकर्षक जीवंत और एनिमेटेड)
• Abusive means extremely offensive and insulting. (अत्यंत आपत्तिजनक और अपमानजनक)
• The option that is nearest in meaning to the underlined word 'vitriolic' is 'abusive'.
• Example - Welsh pharmacists are reporting an increase in abusive and aggressive behaviour.

The correct answer is 'bankrupt'.

Key Points:- 

• Bankrupt means declared in law as unable to pay their debts.
• Example: He went bankrupt after only a year in business.
• Broke means having completely run out of money.
• Example: Many small businesses went broke (= lost all their money) during the recession.
• Therefore, the option that is nearest in meaning to the underlined word 'broke' is 'bankrupt'.
• Hence, option 1 is the correct answer.​

​

Additional Information

• Rich means having a great deal of money or assets; wealthy.
• Making a profit means money that is earned in trade or business after paying the costs of producing and selling goods and services.
• Having liabilities means a company's legal financial debts or obligations that arise during the course of business operations.

Hinglish 

• Bankrupt मतलब कानून में अपने कर्ज का भुगतान करने में असमर्थ घोषित किया गया है।
• उदाहरण: He went bankrupt after only a year in business.
• Broke मतलब पूरी तरह से पैसे खत्म हो जाना।
• उदाहरण: Many small businesses went broke (= lost all their money) during the recession.
• Rich मतलब बहुत सारा धन या संपत्ति होना; अमीर।
• Making a profit मतलब वह धन जो व्यापार या व्यवसाय में वस्तुओं और सेवाओं के उत्पादन और बिक्री की लागत का भुगतान करने के बाद अर्जित किया जाता है।
• Having liabilities मतलब कंपनी के कानूनी वित्तीय ऋण या दायित्व जो व्यवसाय संचालन के दौरान उत्पन्न होते हैं।
• रेखांकित शब्द 'broke' के अर्थ में निकटतम विकल्प 'bankrupt' है।
• अतः विकल्प 1 सही उत्तर है।

The correct answer is "foul" 

Key Points

• Look at the meaning of the word in the question:
• Nasty- very bad or unpleasant.
• Look at the meaning of the marked options:
• Foul- having a disgusting smell or taste or being dirty.
• Look at the meanings of the words in the options:
• Nice- pleasant or attractive.
• Fastidious- very concerned about matters of cleanliness.
• Finicky- showing or requiring great attention to detail.
• The option that is nearest in meaning to the underlined word 'nasty' is 'foul'.
• Look at the example:
• He loves doing foul things.

Hence, the correct option: foul

Hinglish

• Fastidious- बहुत बारिक्यों में ध्यान देना
• Finicky- बहुत बारिक्यों में ध्यान देना

The correct answer is "gather" 

Key Points

• Look at the meaning of the given word in the question:
• Muster- to collect or assemble.
• Look at the meaning of the selected word:
• ​Gather-come together; assemble or accumulate.
• Look at the meaning of the other words:
• Injure- to harm or impair.
• Spoil-  to diminish or destroy the value or quality of.
• Maim- to wound or injure (a person or animal) so that part of the body is permanently damaged.
• The option that is nearest in meaning to the underlined word 'muster' is ' gather'.
• Example:
• ​We're still gathering organic materials such as tree leaves to add to our garden beds.
• They gather stones to kill their stupid mother.

Hence, the correct answer: gather

Hinglish

• Muster- इक्कठा करना
• Maim- किसी के सरीर क किसी भाग को घायल कर देना

Option 4 is the right answer.

Farcical means very silly, unlikely, or unreasonable.

Foolish means lacking good sense or judgement; unwise.

Preposterous means contrary to reason or common sense; utterly absurd or ridiculous.

Rational means having the ability to reason.

Absurd means wildly unreasonable, illogical, or inappropriate.

The option that is opposite in meaning to the underlined word 'absurd' is 'rational'.

Example - His conversations are always rational.

Option 3 is the right answer.

Dissident means a person who opposes the official policy.

Agitator means a person who urges others to protest or rebel.

Rebel means a person who rises in opposition or armed resistance against an established government or leader.

Conformist means a person who conforms to accepted behaviour or established practices.

Revolutionary means engaged in or promoting political revolution.

The option that is opposite in meaning to the underlined word 'dissident' is ' conformist'.

Example - The politician was a conformist.

The correct answer is "incisive"

Key Points

• Let's look at the meaning of the word given in the question:
• Incisive- quick and direct.
• Let's look at the meaning of the selected word:
• Vague- of uncertain, indefinite, or unclear character.
• Let's look at the meaning of the other words:
• Penetrating- clearly heard through or above other sounds.
• Trenchant- forcefully and effectively expressed.
• Precise- exact, accurate, and careful about details.
• The option that is opposite in meaning to the underlined word 'incisive' is 'vague'.
• Example- 
• His directions were vague.

Hence, the correct answer is Vague

The correct answer is 'thrifty.'

Key Points

• The given word 'prodigal' means spending money freely and rather wastefully. (फ़िज़ूलख़र्च, ख़र्चीला)
• ​Let's see the meaning of other given options:-
• 'Extravagant' means spending or costing too much money. (फ़िजूलख़र्च या बेहद महँगा)
• 'Profligate' means wasting money, time, etc., or using it in a careless way. (समय, धन आदि का बेपरवाही से प्रयोग करनेवाला; फ़िज़ूलख़र्च)
• 'Wasteful' means using more of something than necessary; causing waste. (फ़ज़ूलख़र्च, ख़र्चीला)
• 'Thrifty' means using money and other resources carefully and not wastefully. (कमख़र्च, किफ़ायती, किफ़ायतशार)
  

Hence, the correct answer is option 4.

<br>

Additional Information

• The antonyms of the word 'prodigal' are "thrifty, miserly, niggardly".
• The synonyms of the word 'prodigal' are "extravagant, unthrifty, wasteful".
• Example of 'prodigal​' in a sentence:
• He has been prodigal with company funds.

The correct answer is 'one-sided.'

Key Points

• The given word 'reciprocal' means given, felt, or done in return. (बदले में दिया, महसूस किया हुआ)
• ​Let's see the meaning of other given options:-
• 'Mutual' means felt or done equally by both people involved. (दोनों पक्षों द्वारा समान रूप से एक दूसरे के प्रति अनूभूत या संपादित, पारस्‍परिक, आपसी)
• 'One-sided' means showing only one point of view; not equal. (एकपक्षीय, इकतरफ़ा)
• 'Shared' means to divide something between two or more people. (किसी वस्‍तु को दो या अधिक लोगों में बाँटना)
• 'Corresponding' means related or similar to something. (किसी से संबंधित या उसके समान; मेल खाता हुआ)
  

Hence, the correct answer is option 2.

<br>

Additional Information

• The antonyms of the word 'reciprocal' are "one-sided, noncomplementary, nonreciprocal".
• The synonyms of the word 'reciprocal' are "mutual, shared, joint".
• Example of 'reciprocal' in a sentence:
• Our relationship is based on reciprocal respect.

The correct answer is 'boring.'

Key Points

• The given word 'stimulating' means interesting and exciting. (रोचक और उत्तेजक)
• ​Let's see the meaning of other given options:-
• 'Arousing' means causing a particular reaction in people. (दूसरे व्‍यक्तियों में कोई प्रतिक्रिया विशेष जागृत करना; उत्तेजित करना)
• 'Invigorating' means making one feel strong, healthy, and full of energy. (किसी व्‍यक्ति को स्‍वस्‍थ और ऊर्जस्वी बनाना, किसी का बलवर्धन करना)
• 'Boring' means not at all interesting; dull. (उबाऊ, नीरस, शुष्‍क)
• 'Stirring' means to make somebody feel a strong emotion. (किसी की भावनाओं को भड़काना)
  

Hence, the correct answer is option 3.

<br>

Additional Information

• The antonyms of the word 'stimulating' are "boring, unexciting, uninteresting".
• The synonyms of the word 'stimulating' are "interesting, energetic, lively".
• Example of 'stimulating' in a sentence:
• Aerobics is one of the most stimulating forms of exercise.

The correct answer is 'rare.'

Key Points

• The given word 'widespread' means found or happening over a large area; affecting a large number of people. (दूर-दूर तक फैला हुआ, व्‍याप्‍त; अनेक लोगों को प्रभावित करने वाला, व्‍यापक)
• ​Let's see the meaning of other given options:-
• 'Endemic' means a disease or condition regularly found among particular people or in a certain area. (किसी विशेष स्‍थान या व्‍यक्ति वर्ग में नियमित रूप से पाया जाने वाला और जिससे छुटकारा मुश्किल है; जातीय, स्‍थानिक)
• 'Pervasive' means that is present in all parts of something. (सर्वत्र, व्‍याप्‍त, व्‍यापक)
• 'Common' means happening or found often or in many places; usual. (प्रायः या बहुत सारे स्‍थानों पर पाया जाने या होने वाला; सामान्‍य, आम)
• 'Rare' means not done, seen, happening, etc. very often. (दुर्लभ, विरल)
  

Hence, the correct answer is option 4.

<br>

Additional Information

• The antonyms of the word 'widespread' are "rare, limited, restricted".
• The synonyms of the word 'widespread' are "expansive, extended, extensive".
• Example of 'widespread' in a sentence:
• The allegations received widespread media coverage.

The correct answer is 'apathetic.'

Key Points

• The given word 'vehement' means showing very strong (often negative) feelings, especially anger. (भावना, विशेषतः क्रोध की दृष्टि से प्रचंड, उग्र)
• ​Let's see the meaning of other given options:-
• 'Animated' means interesting and full of energy. (रोचक और जोशीला)
• 'Apathetic' means showing or feeling no interest, enthusiasm, or concern. (कोई दिलचस्पी, उत्साह या चिंता नहीं दिखाना या महसूस करना)
• 'Fervent' means having or showing very strong feelings about something. (जोशीला, उत्‍साही)
• 'Vigorous' means strong, healthy, and full of energy. (ऊर्जायुक्त, ज़ोरदार, जोशभरा)
  

Hence, the correct answer is option 2.

<br>

Additional Information

• The antonyms of the word 'vehement' are "apathetic, hesitant, understated".
• The synonyms of the word 'vehement' are "aggressive, violent, energetic".
• Example of 'vehement​' in a sentence:
• Despite vehement opposition from her family, she quit school and became an actress.

Here the correct answer is Amenable.

Key Points:-

• Obstinate means very difficult to change or overcome. (बदलना या दूर करना बहुत मुश्किल)
• Stubborn means refusing to change an opinion or course of action. (किसी राय या कार्रवाई के पाठ्यक्रम को बदलने से इनकार करना)
• Amenable means someone who is agreeable or willing to be persuaded. (कोई ऐसा व्यक्ति जो राजी हो या राजी हो जाए)
• Example - He has been amenable since his childhood.
• Rigid means unable to bend or be forced out of shape; not flexible. (झुकने में असमर्थ या आकार से बाहर होने के लिए मजबूर होना; लचीला नहीं)
• The option that is opposite in meaning to the underlined word 'Obstinate' is 'Amenable'.

Option 4 is the right answer.

Key Points 

• Renowned means known or talked about by many people; famous.
• Distinguishable means clear enough to be recognized or identified as different.
• Eminent means standing above others in some quality or position: prominent.
• Unknown means one that is not known or not well-known especially: a person who is little known (as to the public).
• Prominent means important; famous.

The option that is opposite in meaning to the underlined word 'prominent' is ' unknown '.

Example -- How had he, a complete unknown, achieved this transformation?

The right answer is Option "1".

Key Points

• The main clause needs a simple past tense verb 'arrived', instead of the past perfect 'had arrived'.
• The preposition 'before' is followed by a recent action 'protests shook'.
• Thus, it should be 'He arrived at Cairo', instead of 'he had arrived at Cairo'.
• The correct sentence: He arrived at Cairo a few months before protests shook the Arab world.

The correct answer is '(c).'

Key Points

• The phrase As we 'do' when we were 30 has mixed tenses.
• As we 'do' when we were 30 मुहावरा मिश्रित काल का है।
• In this phrase, past tense has come after the present tense.
• इस वाक्यांश में, वर्तमान काल के बाद भूतकाल आया है।
• This phrase should be in the past tense so the past tense must be followed by the past tense.
• यह वाक्यांश भूतकाल में होना चाहिए, इसलिए भूत काल के बाद भूत काल होना चाहिए।
• Therefore, the use of 'do' in Part (c) of the sentence should be replaced with 'did' to make it grammatically correct.
• Therefore, the correct answer is '(c).'
  

​The correct sentence: Most of us who are older competitive runners are not able to race anywhere at the same speed as we did when we were 30.

Additional Information

• The four present tenses are the simple present, present progressive, present perfect and present perfect progressive.
• When any of these tenses are used in an independent clause, the verb in the dependent clause can be present tense, past tense or future tense.
• जब इनमें से किसी भी काल का प्रयोग स्वतंत्र उपवाक्य में किया जाता है, तो आश्रित उपवाक्य में क्रिया वर्तमान काल, भूतकाल या भविष्य काल हो सकती है।
• Example: Ram waits patiently while his father books the tickets.
• ​If the action in the dependent clause occurred before the action in the independent clause, the past perfect is usually the most appropriate tense for the dependent clause.
• यदि आश्रित उपवाक्य में क्रिया स्वतंत्र उपवाक्य में क्रिया से पहले हुई हो, तो आश्रित उपवाक्य के लिए भूतकाल उत्तम आमतौर पर सबसे उपयुक्त काल होता है।​
• Example: Maria arrived at 5 p.m. but Ravi had closed the store.

Option 2 is the right answer i.e. b.

 Key Points

• 'Lest' as the conjunction has a negative meaning. So, it cannot be used with another negative 'do not'.
• The verb that always follows 'lest' is 'should'.
• Thus part b has an error. The correct answer is option 2.

The correct sentence would, thus, be -- Work hard lest you should fail.

Additional Information

• If one negative word changes the meaning of a word or sentence, then a second negative word would change the meaning back to its original state.
• It's a negation of the negation.
• Example: I don't want nothing for my birthday: Incorrect

                                      I don't want anything for my birthday: Correct

The correct answer is "a"

Key Points

• There is a problem regarding prepositions:
• Look at the difference between "Home of" and "Home to"
• 'Home of' means a general term, saying that usually, these plants live in such a habitat.
• 'Home to' means that currently, these plant species live in such a habitat.
• Example: Australia is home to some dangerous animals.
• The given sentence is about the Eastern Ghats is a 'home to' 2600 plant species.
• Also, the eastern ghats are taken as one unit, which needs a singular verb -- 'is'

So, the correct sentence is- The Eastern Ghats is home to 2600 plant species and this habitat fragmentation can pose a serious threat to endemic plants.

The correct answer is '(d).'

​

• The given sentence gives an explanation about a turbidity current and its movement.
• दिया गया वाक्य एक turbidity current और उसकी movement के बारे में स्पष्टीकरण देता है।
• The sentence has used the verbs and other parts of speech correctly and has no errors.
• वाक्य में क्रियाओं और भाषण के अन्य भागों का सही उपयोग किया गया है और इसमें कोई त्रुटि नहीं है।

Therefore, the correct answer is '(d).'

​The correct sentence: Turbidity current is a fast-moving current that sweeps down submarine canyons, carrying sand and mud into the deep sea.

Additional Information

• A helping verb (also known as an auxiliary verb) is used with a main verb to help express the main verb's tense, mood, or voice.
• एक helping verb (जिसे auxiliary verb के रूप में भी जाना जाता है) का उपयोग मुख्य क्रिया के साथ मुख्य क्रिया के काल, मनोदशा या आवाज को व्यक्त करने में मदद के लिए किया जाता है।
• The main helping verbs are "to be," "to have," and "to do."
• They appear in the following forms: To Be: am, is, are, was, were, being, been, will be
  

                                                         To Have: has, have, had, having, will have.

• Example: Peter has been singing for an hour.

Option 3 is the right answer. It has an error.

Every  'one' shows that 'one' - a singular form of the boys - is indicated. 

Hence, it requires a singular verb.

In the present tense, nouns and verbs form plurals in opposite ways: nouns ADD an S to the singular form; verbs REMOVE the S from the singular form. Example : singular—the dog chases the cat / plural—the dogs chase the cat.

So, the verb will be  'loves'.

The correct sentence will be -- Every one of the boys loves to ride.

Option 2 is the right answer.

Neither...nor  conjunction joins two singular nouns 'praise and blame' - it needs a singular verb.

In the present tense, nouns and verbs form plurals in opposite ways: nouns ADD an S to the singular form; verbs REMOVE the S from the singular form. Example : singular — the dog chases the cat/ plural —the dogs chase the cat.

So, the verb in the given sentence should be singular - 'seems'.

The correct sentence is -- Neither praise nor blame seems to affect him.

The correct answer is '(d).'​

Key Points

• Let us explore some rules related to the word 'many' : 
• आइए हम 'many' शब्द से संबंधित कुछ नियमों को देखें:​
• Many a + Sing noun + Sing verb
• Example: Many a man has tried but few men have succeeded.
• Many + Plural noun + Plural verb
• Example: Many students are coming today.
• There is no error in this sentence as it is satisfying all the grammatical rules.
• इस वाक्य में कोई त्रुटि नहीं है क्योंकि यह सभी व्याकरणिक नियमों को संतुष्ट करता है।
• Therefore, the correct answer is '(d).'
  

​The correct sentence: Many a man has succumbed to this temptation.

Additional Information

• A helping verb (also known as an auxiliary verb) is used with a main verb to help express the main verb's tense, mood, or voice.
• एक helping verb (जिसे auxiliary verb के रूप में भी जाना जाता है) का उपयोग मुख्य क्रिया के साथ मुख्य क्रिया के काल, मनोदशा या आवाज को व्यक्त करने में मदद के लिए किया जाता है।
• The main helping verbs are "to be," "to have," and "to do."
• They appear in the following forms: To Be: am, is, are, was, were, being, been, will be
  

                                                         To Have: has, have, had, having, will have.

• Example: Peter has been singing for an hour.

Option 2 is the right answer i.e. b.

Key Points

• 'Each speaker' indicates a singular subject that needs a singular verb to agree with it - 'is'.
• In part 'B', the verb is 'are' - a plural, which is incorrect.
• Thus, part b has an error. The correct answer is option 2.

The correct sentence is - A time slot of fifteen minutes is a**llowed to each speaker.

Additional Information

• When a plural number applies to time, height, weight, distance etc. take it as a single unit and apply a singular verb.
• ​Example: Twenty five kilometers is not a small distance to walk.

The correct answer is '(c).'

Key Points

• 'Either' is used to indicate 'one' or the other of two people or things and it needs a singular verb.
• 'Either' का प्रयोग एक या दो लोगों या चीजों में से दूसरे को इंगित करने के लिए किया जाता है और इसे singular verb की आवश्यकता होती है।
• However, in Part 'c', the word 'were' is used which is a plural helping verb.
• हालाँकि, Part 'c' में 'were' शब्द का प्रयोग किया गया है जो एक plural helping verb है।
• The correct word to be used is 'was' [ since the use of 'asked ' indicates the past tense].
• Therefore, the use of 'were' in Part (c) of the sentence should be replaced with 'was' to make it grammatically correct.
• Therefore, the correct answer is '(c).'
  

​The correct sentence: He asked whether either of the brothers was at home.

Additional Information

• A helping verb (also known as an auxiliary verb) is used with a main verb to help express the main verb's tense, mood, or voice.
• एक helping verb (जिसे auxiliary verb के रूप में भी जाना जाता है) का उपयोग मुख्य क्रिया के साथ मुख्य क्रिया के काल, मनोदशा या आवाज को व्यक्त करने में मदद के लिए किया जाता है।
• The main helping verbs are "to be," "to have," and "to do."
• They appear in the following forms: To Be: am, is, are, was, were, being, been, will be
  

                                                         To Have: has, have, had, having, will have.

• Example: Peter has been singing for an hour.

The correct answer is- 'to be too old to do things.'

Key Points:-

• Let's look at the meaning of the given idiom:-
• Be over the hill - used for describing someone who is old and no longer useful or able to do something well. (Be over the hill - किसी ऐसे व्यक्ति का वर्णन करने के लिए उपयोग किया जाता है जो बूढ़ा हो गया है और अब उपयोगी नहीं है या कुछ अच्छा करने में सक्षम नहीं है।)
• Example: I don’t think of myself as being over the hill yet.
• Thus, the correct answer is option 3.

Therefore, the correct meaning of the given idiom is: To be too old to do things.

The correct answer is- 'to stop yourself from saying something because it would be better not to.'

Key Points

• Let's understand the meaning of the given idiom:
• Bite your tongue means to make a desperate effort to avoid saying something. (Bite your tongue का मतलब है कुछ कहने से बचने के लिए बेताब प्रयास करना।)
• Example: When he was sneering at his assistants and praising himself, I had to bite my tongue from making a retort.
• From the meaning and example, we can say the correct answer is 'to stop yourself from saying something because it would be better not to.'

Thus option 1 is the most appropriate answer

The correct answer is- 'to choose to ignore behaviour that you know is wrong.'

Key Points

• Let's understand the meaning of the given idiom:
• To turn a blind eye means to pretend not to notice. (To turn a blind eye का अर्थ है ध्यान न देने का नाटक करना।)
• Example: Many leaders turn a blind eye to criminal activities in order to get their votes.
• From the meaning and example, we can say the correct answer is 'to choose to ignore behaviour that you know is wrong.'

Thus option 4 is the most appropriate answer

The correct answer is- 'writings in newspapers that try to influence people's opinion by using strong language and false information.'

Key Points

• Let's understand the meaning of the given idiom:
• 'Yellow journalism' is the use of sensational headlines, rather than factual news, to capture a reader's attention. ('Yellow journalism' पाठक का ध्यान आकर्षित करने के लिए तथ्यात्मक समाचारों के बजाय सनसनीखेज सुर्खियों का उपयोग है।)
• Example: The film magazines indulge in yellow journalism to increase their viewership.
• From the meaning and example, we can say the correct answer is 'writings in newspapers that try to influence people's opinion by using strong language and false information.'

Thus option 3 is the most appropriate answer

Additional Information

• Let's learn about the origin of the idiom:
• The term yellow journalism came from a popular New York World comic called 'Hogan's Alley,' which featured a character in a yellow dress named the 'the yellow kid.' (yellow journalism शब्द न्यूयॉर्क वर्ल्ड की एक लोकप्रिय कॉमिक 'होगन्स एले' से आया है, जिसमें 'द येलो किड' नामक पीले रंग की पोशाक में एक चरित्र दिखाया गया था।)

The correct answer is- 'to be extremely happy.'

Key Points

• Let's understand the meaning of the given idiom:
• To be in seventh heaven means attaining a state of endless bliss. (To be in seventh heaven का अर्थ है अनंत आनंद की स्थिति प्राप्त करना।)
• Example: A full day in a resort with all three meals is just seventh heaven.
• From the meaning and example, we can say the correct answer is 'to be extremely happy.'

Thus option 2 is the most appropriate answer

Option 1: RQSP is the right answer.

Key Points

• The sentence is about monitoring the situation about the allegations.
• The sequence of the phrases to make a complete sentence is -- we are deeply concerned (R), starting with the pronoun 'we', by the disturbing allegations **(Q)**and will continue to (S) closely monitor the situation (P).
• The correct answer is option 1.

​The correct sentence is: We are deeply concerned by the disturbing allegations and will continue to closely monitor the situation.

Option 3:QPSR is the right answer.

Key Points

• The sentence is about using aromatherapy to relieve nausea, pain and stress.
• The sequence of the phrases to make a complete sentence is-- aromatherapy may also help (Q) relieve nausea, pain and stress (P) but patients are cautioned against (S) using lavender oil on their skin (R).
• Thus the correct answer is option 3.

The correct sentence is: Aromatherapy may also help relieve nausea, pain and stress but patients are cautioned against using lavender oil on their skin.

Option 2: QSRP is the right answer.

Key Points

• The sentence is about a plea filed against the online sale of drugs and prescription medicines.
  

The sequence of the phrases to make a complete sentence is-- the plea filed through the advocate (Q) submitted that the sale of drugs and prescription medicines (S) online is illegal and (R) without any mandate of law (P).

The right option is 4 PSQR.

Key Points

• The sentence is about the co-existence of humans and machines for millennia.
• The sequence of the phrases to make a complete sentence is -- humans and machines have co-existed (P) at the physical level for millennia (S) dating back to the invention of (Q) the potter's wheel in ancient Mesopotamia (R).

Option 4 is the right answer: SPQR.

Key Points

• The sentence is about the surge of global markets due to robust economic data.
• The sequence of the phrases to make a complete sentence is -- global markets also witnessed **(S)**a sell-off as US Treasury yields (P) surged to multi-year highs (Q) on robust economic data (R).
• Thus option 4 is the correct answer.

The correct sentence is: Global markets also witnessed a sell-off as US Treasury yields surged to multi-year highs on robust economic data.

The correct answer is 'For pleasure, enhanced capability and holistic growth​.'

Key Points

• Let us look at the first two lines of the passage:
• Studies serve for delight, for ornament, and for ability. Their chief use for delight is in privateness and retiring; for ornament, is in discourse; and for ability, is in the judgment, and disposition of business.
• Therefore, according to the author, one should study for pleasure, enhanced capability and holistic growth.
• So, the correct option is 'For pleasure, enhanced capability and holistic growth​.'

 Additional Information 

• The meaning of the word 'discourse' is communication in speech or writing.
• Example: This is a discourse upon the nature of life after death.

The correct answer is 'Because it reflects idleness.'

Key Points

• Let us look at the fourth line of the passage:
• To spend too much time in studies is sloth; to use them too much for ornament, is affectation; to make judgment wholly by their rules, is the humour of a scholar.
• Therefore, the author does not recommend too much of studies because it reflects idleness.
• So, the correct option is  'Because it reflects idleness.'

Additional Information 

• The meaning of the word 'sloth' is a reluctance to work or make an effort; laziness.
• Example: The report criticizes the government's sloth in tackling environmental problems.

The correct answer is 'By experience.'

Key Points

• Let us look at the fifth line of the passage:
• They perfect nature, and are perfected by experience: for natural abilities are like natural plants, that need pruning, by study; and studies themselves do give forth directions too much at large, except they are bounded in by experience.
• Therefore, according to the author, the studies can be perfected by experience.
• So, the correct option is 'By experience.'

Additional Information 

• The meaning of the word 'Forth' is (from a place) out or away, or (from a point in time) forward.
• Example: They set forth on their travels in early June.

The correct answer is 'Cunning​.'

Key Points 

• Let us look at the sixth line of the passage:
• Crafty men condemn studies, simple men admire them, and wise men use them; for they teach not their own use; but that is a wisdom without them, and above them, won by observation.
• Crafty means cunning/sly/ clever, especially in a dishonest or secret way.
• Therefore, cunning kinds of human beings denounces studies.
• So, the correct option is 'Cunning​.'

Additional Information

• The meaning of the word 'denounce' is to criticize something or someone strongly and publicly.
• Example: The government's economic policy has been denounced on all sides.

The correct answer is 'evaluate and understand​​.'

Key Points

• Let us look at the last line of the passage:
• Read not to contradict and confute; nor to believe and take for granted, nor to find talk and discourse, but to weigh and consider.
• Therefore, according to the author, one should read to evaluate and understand.
• So, the correct option is 'evaluate and understand​​.'

Additional Information 

• The meaning of the word 'confute' is to prove a person or an argument to be wrong.
• Example: He confuted his opponents by facts and logic.

Option 2 is the right answer.

Key Points 

• Pronounced means something that is pronounced and is very noticeable / to enunciate or articulate sounds, words, etc. (कुछ ऐसा जो उच्चारित किया जाता है और बहुत ही ध्यान देने योग्य / ध्वनियों, शब्दों आदि को स्पष्ट या स्पष्ट करने के लिए होता है)
• Announced means to make a formal public statement about a fact, occurrence, or intention. (किसी तथ्य, घटना या इरादे के बारे में औपचारिक सार्वजनिक बयान देना)
• Promulgated means to promote or make widely known (an idea or cause). (प्रचार करना या व्यापक रूप से ज्ञात करना (एक विचार या कारण))
• Issued means supply or distribute (something) for use or sale. (उपयोग या बिक्री के लिए आपूर्ति या वितरण (कुछ)
• The given sentence is about the election commission giving some information about some event to the public.
• So, the right word is -- 'announced'.

The correct sentence is --  The Election Commission on Saturday announced that the Assembly elections in five states will be held from November 12 to December 7.

The correct answer is 'met with'.

Key Points

• 'Met with' means to unexpectedly experience trouble, difficulty, danger, etc.
• Example: I heard she'd met with an accident.
• Therefore, the most appropriate option to be filled in the given blank is 'met with' because it indicates that the victims experienced an accident.
• Hence, option 1 is the correct answer.

 

Complete sentence: The victims were fruit vendors and they were going in an auto when they met with an accident on the way.

Additional Information

• Let's explore the other given options: 
• Ran into means to meet someone you know when you are not expecting to.
• Experienced means having the skill and knowledge to do something.
• Heard means to receive or become conscious of a sound using your ears.

Hinglish 

• 'Met with' का अर्थ है अप्रत्याशित रूप से परेशानी, कठिनाई, खतरे आदि का अनुभव करना।
• उदाहरण: I heard she'd met with an accident.
• इसलिए, दिए गए रिक्त स्थान को भरने के लिए सबसे उपयुक्त विकल्प 'met with' है क्योंकि यह इंगित करता है कि पीड़ितों ने दुर्घटना का अनुभव किया है।
• अतः विकल्प 1 सही उत्तर है।
• आइए अन्य दिए गए विकल्पों का पता लगाएं:
• Ran into का मतलब है किसी ऐसे व्यक्ति से मिलने के लिए जिसे आप जानते हैं जब आप उम्मीद नहीं करते।
• Experienced का अर्थ है कुछ करने का कौशल और ज्ञान होना।
• Heard का अर्थ है अपने कानों का उपयोग करके किसी ध्वनि को प्राप्त करना या उसके प्रति सचेत होना।

 

पुरा वाक्य: The victims were fruit vendors and they were going in an auto when they met with an accident on the way.

The correct answer is staging.

Key Points

• Let us see the meaning and usage of the words given in options- 
• Performing: present (a form of entertainment) to an audience.
• Sitting: in a seated position.
• Staging: to participate in a public rally to voice opposing opinions.
• Standing: to be in an upright position / vertical.
• The given sentence is about protesting/speaking out against the construction of a new underpass.
• So, the correct word is 'staging'.

Correct sentence: Scores of villagers are staging a sit-in protest against the construction of a new underpass.

Option 4 is the right answer.

Key Points 

• Eating means to put (food) into the mouth and chew and swallow it. (भोजन) मुंह में डालना और चबाना और निगलना)
• Gulping means swallow (drink or food) quickly or in large mouthfuls. (निगलना (पीना या खाना) जल्दी या बड़े कौर में।)
• Swallowing means to enclose or envelop completely. (पूरी तरह से घेरना या घेरना)
• Taking when used before'medicine' means the intake of the prescribed drugs for treating some illness. (किसी बीमारी के इलाज के लिए निर्धारित दवाओं का सेवन)

The correct sentence is -- It is common for patients to stop taking medicine as soon as they start feeling better.

Option 2 is the right answer.

Key Points 

• Rejuvenated means to make someone look or feel young and energetic again. (किसी को फिर से युवा और ऊर्जावान दिखने या महसूस करने के लिए)
• Removed means to move physically, take away. (शारीरिक रूप से स्थानांतरित करने के लिए, दूर ले जाना)
• Displaced means to take the place of something or someone (किसी चीज या किसी की जगह लेना)
• Replaced means to put something or someone in the place of something or someone else. (किसी चीज़ या किसी को किसी चीज़ या किसी और के स्थान पर रखना)
• The given sentence is about a girl becoming better after a tumour [was taken out] from one of her kidneys. So, the correct word is 'removed'.

The correct sentence is -- A four-year-old girl got a new lease of life after doctors at a hospital removed a cancerous tumour from one of her kidneys.

CONCEPT:

Moment of inertia:

• The moment of inertia of a rigid body about a fixed axis is defined as the sum of the product of the masses of the particles constituting the body and the square of their respective distances from the axis of the rotation.
• The moment of inertia of a particle  is

⇒ I = mr2

Where r = the perpendicular distance of the particle from the rotational axis.

• Moment of inertia of a body made up of a number of particles (discrete distribution)

⇒ I = m1r12 + m2r22 + m3r32 + m4r42 + -------

Rotational kinetic energy: 

• The energy, which a body has by virtue of its rotational motion, is called rotational kinetic energy.
• A body rotating about a fixed axis possesses kinetic energy because its constituent particles are in motion, even though the body as a whole remains in place.
• Mathematically rotational kinetic energy can be written as -

⇒ KE $= \frac{1}{2}I{\omega ^2}$

Where I = moment of inertia and ω = angular velocity.

EXPLANATION:

• The moment of inertia of the ring about an axis passing through the center and perpendicular to its plane is given by

⇒ I_ring = MR²

• Moment of inertia of the disc about an axis passing through center and perpendicular to its plane is given by -

$⇒ {I_{disc}} = \frac{1}{2}M{R^2}$

• As we know that mathematically rotational kinetic energy can be written as

$⇒ KE = \frac{1}{2}I{\omega ^2}$

• According to the question, the angular velocity of a thin disc and a thin ring is the same. Therefore, the kinetic energy depends on the moment of inertia.
• Therefore, a body having more moments of inertia will have more kinetic energy and vice - versa.
• So, from the equation, it is clear that,

⇒ Iring > Idisc

∴ Kring > Kdisc

• The ring has higher kinetic energy.

Concept:

Velocity -

The rate of change of displacement is called as the velocity of a particle.

${\rm{Velocity;}}\left( {\rm{v}} \right) = \frac{{Change;in;displacement}}{{Time;taken}}$

$\therefore v = \frac{{{S_2} - {S_1}}}{{{t_2} - {t_1}}}$

Where S₂ = final displacement at time t₂ and S₁ = initial displacement at time t₁.

Acceleration -

The rate of change of velocity is called the acceleration of the body.

$a = \frac{{{v_2} - {v_1}}}{{{t_2} - {t_1}}}$

Where v₂ = Final velocity and v₁ = Initial velocity of an object at time t₂, t₁ respectively

Force -

The product of mass and acceleration is called force.

Force (F) = M × a

Where a is the acceleration of the object and M is mass.

Kinetic energy = KE = $\frac{1}{2}m{V^2}$

Where M is the mass of the object and V is the velocity of the object.

Explanation:

• As the chemical reaction inside the object will create an internal force on the object.
• Internal force doesn’t create acceleration in the body.
• There is no net external force acting on the object.

F_net = M × a = o

So the acceleration of the object (a) = 0

• Since acceleration is zero so the velocity of the object will remain constant always. Hence chemical reactions can’t change the velocity of the centre of mass of the system. So statement 1 is correct.
• As the velocity of each particle of the object is equal to the velocity of the centre of mass of the object.

The velocity of particles of an object with respect to the centre of mass,

V = (velocity of the object) - (velocity of the centre of mass) = 0

So kinetic energy with respect to the centre of mass = KE = $\frac{1}{2}m{V^2} = 0$

Hence Kinetic energy of particles of the object will not change with respect to the centre of mass of the object. So statement 2 is correct.

Hence option 3 is correct**.**

CONCEPT: 

• The movement of energy from one place to other is called energy transfer. Heat transfer mainly takes place due to temperature differences.

There are three modes of Heat transfer.

1. Conduction: The mode of heat transfer in solids where heat transfer takes place without the movement of medium particles is called conduction.
   

For example: By heating one end of a metal rod we can feel hotness at another end. 2. Convection: The mode of heat transfer in fluids where heat transfer takes place due to the movement of particles of the medium is called convection.

For example Heating water in a pot 3. Radiation: The mode of heat transfer where heat is transferred from one place to another without affecting the medium particles is called radiation.

For example: When we place our hand nearby the burning gas stove then we can feel the hotness. This is due to radiation.

EXPLANATION:

• Thermal radiation: The electromagnetic radiation emitted by a body by virtue of its temperature is called thermal radiation or radiant energy.
• All bodies having a temperature above 0 K emit thermal radiation continuously.
• For example, the radiation emitted by red-hot iron or light from a filament lamp is thermal radiation.

Properties of thermal radiation:

• These are electromagnetic waves having a wavelength range from 1µm to 100 um. These are also called infrared waves.
• Like light, thermal radiations travel in straight lines. Thus option 3 is correct.
• These radiations obey the laws of reflection and refraction as light does.
• They show the phenomena of interference, diffraction, and polarisation.
• Thermal radiations produce heat when they are absorbed by a body.

Concept -

Ohm’s law -

At constant temperature, the potential difference across a current-carrying wire is directly proportional to the current flowing through it.

V = R⋅I

Where V = potential difference, R = resistance and I = current.

Explanation -

• If the physical conditions of the conductor (length, temperature, mechanical strain, etc.) remain constant, then the current flowing through the conductor is directly proportional to the potential difference across its two ends i.e. I ∝ R ⇒ V = IR where R is a proportionality constant, known as electric resistance. Therefore, option 1 is correct.
• So, if we make a statement of this, a conducting device obeys Ohm’s law, if its resistance between any two points is independent of the magnitude and polarity of the potential difference applied between those points which happens in metallic conductors.
• Then, in other words, the ratio of V/I, or I/V, remains constant all the time, so that the slope of the curve remains constant. Hence option 2 is correct.
• Some materials and devices which are used in electric circuits do not have the proportionality between voltage and current.
• For Example, consider a diode and plot a graph between voltage and current. When the value of voltage is marked in the reverse direction by keeping the magnitude fixed, it produces the current with a different magnitude in the opposite direction. The relationship between the voltage and current is not linear.
• Therefore, there are some materials that do not support ohm’s law. Hence, option 4 is incorrect.

CONCEPT:

• Conservation of momentum: When no external force acts on the system of several interacting particles, the total linear momentum of the system is conserved. The total linear momentum is the vector sum of the linear momenta of all the particles of the system.

 EXPLANATION:

• Suppose the ball has a mass of “m” and a speed of “v”. As we know that momentum is a vector quantity therefore it has both magnitudes as well as directions.
• When the ball is moving towards the wall, then the momentum is mass × velocity. As we know that momentum is a vector quantity, so it will point in the same direction as velocity.
• After the ball has a perfectly elastic collision with the wall (no loss of energy) the speed of the ball is the same.
• But its velocity is now pointing away from the wall i.e. in the negative direction with respect to the initial case. Therefore its momentum will change.

Before collision -

p = m × v = mv

After collision -

p = m × (- v) = - mv [As velocity is a vector quantity.]

• The net change in momentum is, p_net = mv - (-mv) = 2mv. Therefore, the momentum has changed.
• If we talk about other terms like speed, kinetic energy, and potential energy, all are scalar quantities. Hence, they depend only on magnitude. Therefore these all will remain the same at that instant.

Fe₂O₃ is a compound that doesn’t exhibit a different oxidation number for the same element.

• Fe₂O₃ is a not a spinel, meaning, for one mole of Fe₂O₃ there are no 2 atoms of Iron (Fe) that exist in a +3 oxidation state, and one Fe atom exists in a +2 oxidation state.
• Fe₂O₃ is a simple compound, has Fe in only +3 oxidation states.
• In Pb₃O₄ lead is in +4 and +2 oxidation states, it is a mixture of PbO & PbO₂.
• Again, Mn₂O₃ is a spinel with Mn atoms having +2 and +3 oxidation states.

Soda glass doesn’t have the same hardness or tolerance level to heat as compared to Pyrex glass.

Key Points

• This is because Pyrex is one particular blend of Borosilicate glass that shows high resistance to heat and doesn’t expand as much when heated.
• Glass has a melting point of approximately 1400 °C to 1600 °C. So, it varies according to composition.
• The original Pyrex glass is known to scientists and artists as borosilicate, “boro” for short.
• The main ingredients in the glass are oxides of the elements silicon, sodium, aluminum, and boron.

The correct answer is Boiling is a bulk phenomenon while evaporation is a surface phenomenon.

Key Points

• The surface phenomenon is the phenomenon in which the accumulation of a large number of molecules at the surface of the liquid phase or solid phase is more as compared to the bulk.
• Adsorption is also an example of a surface phenomenon because in this the unbalanced or residual forces are present at the surface.
• Evaporation is a surface phenomenon because the surface of the water will evaporate from the whole water.
• The kinetic energy of the topmost molecules will get dissipated in the air.
• The melting process is also an example of a surface phenomenon.
• A bulk phenomenon is a phenomenon in which the whole of the substance or the compound is involved.
• Boiling is the bulk phenomenon because in this the particles of the bulk of liquid gain energy and then get converted into a gaseous or vapor state.
• The heat energy is transferred to all the particles that are the entire bulk of the liquid.
• When a liquid is boiled the heating of the substance starts from the bottom of the vessel so that the temperature of the whole liquid reaches its boiling point.
• Hence boiling is a bulk phenomenon and evaporation is a surface phenomenon.

The correct answer is Both the physical and chemical properties of diamond and graphite are different.

Key Points

• An allotrope is another form of the same element having different physical properties but the same chemical properties.
• For example, Graphite and diamond are two different allotropes of carbon.
• They are different in physical properties but resemble carbon in chemical properties.

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Additional Information

• Note:
• ​The possibility to make a mistake is that Graphite and Diamond are the allotropes of carbon and they are not the isotopes of each other.
• Allotropes are the different forms of an element having different physical properties while isotopes are the atoms of an element having the same atomic number but different atomic mass.

The raw material that is used in the manufacturing of Portland cement mainly consists of lime, silica, alumina, and iron oxide.

• The first step of manufacturing Portland Cement includes quarrying, followed by Primary Crushing.
• Further, the raw materials are mixed in the right amount, and fed to the kiln system.
• Other materials which are used to manufacture Portland Cement include - shells, chalk, shale, clay, slate, and silica sand.

The correct answer is Water is a nonpolar molecule.

Key Points

• Water is a polar molecule:
• Water is a polar molecule.
• While the overall charge of the molecule is neutral, the orientation of the two positively charged hydrogens (+1 each) at one end and the negatively charged oxygen (-2) at the other end give it two poles.
• This property causes water molecules to be weakly attracted to other water molecules (positive to negative, negative to positive) and results in the cohesion of water to itself.
• Water droplets on a flat piece of glass, for example, form droplets and bead up.​
• This means that the negatively and positively charged particles are unevenly distributed.
• Electrons supply the negative charge, while the atomic nucleus provides a positive charge.
• Water (H₂O) is polar because of the bent shape of the molecule.
• The boiling point of water is 100°C.
• water molecules are polar:

Additional Information

• Hydrogen bonding forms in liquid water because the hydrogen atoms of one water molecule are attracted toward the oxygen atom of a neighboring water molecule; generally, a proton is shared by two lone electron pairs.

The correct answer is Potassium.

Key Points

• Soft Soap is made up of Potassium Hydroxide.
• Soft water feels slippery or slimy as if it does not rinse off.
• It can taste salty due to its prevalent sodium content.
• Soap and detergent will not lather up if used in too great a quantity.
• Soft water leaves no mineral deposits in the shower, bath, or on your dishes.
• Very soft water leaches metals such as lead and copper from pipes, plumbing fixtures, and solder, lending a metallic taste and odor to the water.
• Soft water can be easily identified by its characteristic of forming a lather with soap.
• Soft water has numerous benefits, most of which come from removing or reducing the levels of hard minerals.

Important Points

• Chemical Composition of Soft Water:
• Soft water contains 0 to 17.1 ppm (parts per million) of hard minerals.
• Due to the relative absence of hard minerals, soft water has high sodium content.
• Hard water is surface water that contains more than 50 mg/l of calcium carbonate.
• Soap is a sodium salt or potassium salt of fatty acids having cleansing action in the water.
• Vinegar and baking soda can be used for converting hard water into soft water.

Additional Information

• Generally, hard soaps are made up of Sodium Hydroxide.
• Softsoap has a low melting point.
• Softsoap would lather with soft water as they would lower the concentration of Magnesium and Calcium ions.

CONCEPT:

Acceleration (a) -

• Acceleration is the rate of change of the velocity of an object.

$a = \frac{{dv}}{{dt}} = \frac{{{v_2} - {v_1}}}{{{t_2} - {t_1}}}$

Where v₂ is final velocity at time t₂ and v₁ is final velocity at time t₁.

EXPLANATION:

By using third equation of kinematics

$s = ut + \frac{1}{2}a{t^2}$

Where s = displacement, u = initial velocity, a = acceleration and t = time.

• We can clearly say that, at non-zero constant acceleration for a certain interval of time, distance covered depend upon its initial velocity. Therefore option 1 is correct.
• From above equation it is very much clear that displacement time graph is parabolic in nature, therefore option 3 is incorrect.
• From above equation it is clear that distance covered depend upon its initial velocity. Therefore option 4 is incorrect.

CONCEPT:

Moment of inertia:

• Moment of inertia of a rigid body about a fixed axis is defined as the sum of the product of the masses of the particles constituting the body and the square of their respective distances from the axis of the rotation.
• The moment of inertia of a particle  is

⇒ I = mr2

Where r = the perpendicular distance of the particle from the rotational axis.

• Moment of inertia of a body made up of a number of particles (discrete distribution)

⇒ I = m1r12 + m2r22 + m3r32 + m4r42 + -------

EXPLANATION:

• Moment of inertia of the disc about an axis passing through center and perpendicular to its plane is given by -

$⇒ {I_{disc}} = \frac{1}{2}M{R^2} = 0.5M{R^2}$

• Moment of inertia of the solid sphere about an axis passing through center and perpendicular to its plane is given by -

$⇒ {I_{sphere}} = \frac{2}{5}M{R^2} = 0.4M{R^2}$

• So, from above it is very clear that the moment of inertia of the disc is greater than the moment of inertia of the solid sphere.

CONCEPT:

• The relative density is defined as the ratio of the density of a substance to the density of water.
• Mathematically relative density can be written as,
• $Relative;density = \frac{{Density;of;body}}{{Density;of;water}}$

Let m be the mass of the given substance of volume V and density ρ. Let m₁ be the mass of water of volume V and density ρ₁ at 4°C. Then, m = Vρ and m₁ = Vρ₁

• Relative density, ${\rho _r} = \frac{m}{{{m_1}}} = \frac{{V\rho }}{{V{\rho _1}}} = \frac{{\rho ;}}{{{\rho _{1;}}}};$

EXPLANATION:

Given = ρ_v = 4 and ρ_m = 3

If two liquids of same masses but densities ρ₁ and ρ₂ respectively are mixed, then the density of the mixture is

${\rho _m} = \frac{{2{\rho _1}{\rho _2}}}{{\left( {{\rho _1} + {\rho _2}} \right)}}$

$3 = \frac{{2{\rho _1}{\rho _2}}}{{\left( {{\rho _1} + {\rho _2}} \right)}}$

$\Rightarrow 3\left( {{\rho _1} + {\rho _2}} \right) = 2{\rho _1}{\rho _2}$

$\Rightarrow 3{\rho _1} + 3{\rho _2} = 2{\rho _1}{\rho _2}$     ----(1)

If two liquids of same volume but densities ρ₁ and ρ₂ respectively are mixed, then the density of the mixture is

${\rho _v} = \frac{{{\rho _1} + {\rho _2}}}{2}$

$4 = \frac{{{\rho _1} + {\rho _2}}}{2}$

⇒ ${\rho _1} + {\rho _2} = 8$       ----(2)

On solving (1) and (2) we get

${\rho _1} = 6,{\rho _2} = 2$

Concept:

 Average velocity -

• The average velocity of an object is its total displacement divided by the total time taken.

 

${v_{av}} = \frac{{Total;displacement}}{{Total;time;taken}}$

Calculation:

Given - Distance from starting point to Bengaluru = 50 km and time taken for this round trip = 2 hours.

A car starts from Bengaluru, goes 50 km in a straight line towards south, immediately turns around and returns to Bengaluru i.e. it reach’s to its starting point.

It means displacement is zero as displacement is defined as the difference between the final and initial position of the object in a given time.

As average velocity is defined as,

$Avergae;velocity = \frac{{Total;displacement}}{{Total;time}} = \frac{{50 + \left( { - 50} \right)}}{{2;}} = 0$

Important points -

• The magnitude of displacement is equal to the minimum possible distance between two positions. So distance ≥ Displacement.
• For a moving particle, distance can never be negative or zero while displacement can be. (Zero displacement means that body after motion has come back to initial position). i.e., Distance > 0 but Displacement > = or < 0.
• For motion between two points displacement is single-valued while distance depends on the actual path and so can have many values.
• For a moving particle, distance can never decrease with time while displacement can. A decrease in displacement with time means the body is moving towards the initial position.

CONCEPT:

There are two types of Kirchoff’s Laws:

Kirchoff’s first law:

• This law is also known as junction rule or current law (KCL). According to it the algebraic sum of currents meeting at a junction is zero i.e. Σ i = 0.
• In a circuit, at any junction the sum of the currents entering the junction must be equal the sum of the currents leaving the junction.
• This law is simply a statement of “conservation of charge” as if current reaching a junction is not equal to the current leaving the junction, charge will not be conserved.

Kirchoff’s second law:

• This law is also known as loop rule or voltage law (KVL) and according to it “the algebraic sum of the changes in potential in complete traversal of a mesh (closed loop) is zero”, i.e. Σ V = 0.
• This law represents “conservation of energy” as if the sum of potential changes around a closed loop is not zero, unlimited energy could be gained by repeatedly carrying a charge around a loop.
• If there are n meshes in a circuit, the number of independent equations in accordance with loop rule will be (n - 1).

EXPLANATION:

• From above it clear that "The sum of emf’s and potential differences around a closed loop equals zero" is a consequence of conservation of energy

CONCEPT:

Least Count:

• Least Count of an instrument is the smallest measurement that can be taken using an instrument. In other words, it is the smallest change an instrument can measure.
• For example, the ruler can measure a minimum 1 mm length. Therefore ruler L.C. is 1 mm.

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Least Count vs Precision:

• L.C. is directly related to precision. If an instrument has a small L.C, that means it is more precise.

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Formula to calculate least count is:

• Least Count for an instrument is calculated by dividing main scale reading with number of divisions i.e.

Instrument least Count = Main Scale least Count / Divisions in secondary Scale

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EXPLANATION:

• The precision of a measuring tool is reflected in significant figures in the value.
• Since 1 m = 1000 mm
• As the given scale is a meter scale so it can measure 1000 mm with a least count of 1mm.
• The precision of any measuring tool depends on the size of its measurement increments.
• The smaller is the measurement increment, the more precise will be the tool.
• The number having more digits after the points will be more precise because it can measure the very small differences in length. So option 3 is correct which is having 3 digits after the points.

CONCEPT:

First Law of Thermodynamics:

• It is a statement of conservation of energy in thermo dynamical process.
• According to it heat given to a system (ΔQ) is equal to the sum of increase in its internal energy (ΔU) and the work done (ΔW) by the system against the surroundings.

i.e ΔQ = ΔU + ΔW          [∴ ΔW = p ΔV]

• It makes no distinction between work and heat as according to it the internal energy (and hence temperature) of a system may be increased either by adding heat to it or doing work on it or both.

EXPLANATION:

• According to question, if the work done on the system or by the system is zero which is only possible when system has constant volume (ΔV = 0) the term –PΔV = 0 and work is equal to zero.
• Thus, in the equation ΔU = ΔQ + ΔW = ΔQ + 0 = ΔQ
• ΔU = ΔQ
• The internal energy is equal to the heat of the system. Hence option 1 is correct.

Concept-

Obstruction offered to the flow of current is known as resistance. When two resistors are connected in series then the equivalent resistance is R_ser = R₁ + R₂

When two resistors are connected in parallel then the equivalent resistance is

\(\frac{1}{{{R}{para}}}=~\frac{1}{{{R}{1}}}+\frac{1}{{{R}_{2}}}\)

Explanation-

From the above figure it is very much clear that 2 Ω, 4 Ω and 8 Ω are in parallel combination.

∴ Equivalent resistance is

\(\frac{1}{{{R}{para}}}=~\frac{1}{{{R}{1}}}+\frac{1}{{{R}{2}}}+\frac{1}{{{R}{3}}}\)

$\frac{1}{{{R_{para}}}} = ;\frac{1}{{2{\rm{;\Omega }}}} + \frac{1}{{4{\rm{;\Omega }}}} + \frac{1}{{8{\rm{;\Omega }}}} = ;\frac{{4 + 2 + 1}}{8} = \frac{7}{8}$

${R_{para}} = \frac{8}{7}{\rm{\Omega }}$

From above figure it is very clear that 8/7 Ω and 1 Ω are in series.

∴ R_ser = R₁ + R₂

${R_{ser}} = \frac{8}{7} + 1 = \frac{{8 + 7}}{7} = \frac{{15}}{7}{\rm{\Omega }}$

Concave lens –

• A concave lens is thin in middle and thick at the edges.
• A concave lens is a spherical lens whose two surfaces are concave or bent inward.
• A concave lens is also know known as a diverging lens.

Convex lens –

• A convex lens is thick in middle and thin at the edges.
• A convex lens is a spherical lens whose two surfaces are bent outwards.
• A convex lens is also know known as a converging lens.

Explanation –

• The nature of the image formed by the convex lens is real and inverted but in one case when the object is placed between the pole and the focus of the convex lens the image formed is virtual and erect. Therefore option 1 is correct.
• The nature of the image formed by the concave lens is always virtual and erect. Therefore option 2 is incorrect.
• A convex lens can produce an image equal, greater and smaller than the size of the object is true. Therefore option 3 is correct.
• The nature of the image formed by the concave lens is always virtual and erect and diminished in size. Therefore option 4 is correct.

CONCEPT:

Specific heat or specific heat capacity of a body:

• The amount of heat energy required to raise the temperature of unit mass of a body through 1° C (or K) is called specific heat of the material of the body.
• It is generally denoted by S.

Q = mS∆T              

Where Q = heat required, ∆T = change in temperature and m = mass of the body

Latent heat:

• The amount of heat required to change the state of unit mass m of the substance at constant temperature is called latent heat of the substance.
• It is written as: Q = mL, where L is the latent heat.
• Latent heat is also called as heat of Transformation.

EXPLANATION:

10 g of ice at -10° C

First it will convert into 10 g of ice at 0° C.

∴ Heat required (Q₁) = m_iS_i∆T              

Here, ΔT = temperature change = 0° - (-10° C) = 10° C

Mass of ice (m) = 10 g

Specific heat of ice (S_i) = 0.5 cal/gram ° C

Hence,

Q₁ = 10 × 0.5 × 10              

Q₁ = 50 cal

Then 10 g of ice will converted into 10 g of water.

∴ Latent heat required is

Q₂ = mL

Latent heat of melting of ice = 80 Calories / gram

∴ Q₂ = 10 × 80

Q₂ = 800 cal

Now total amount of water = 10 g +10 g =20 g

This 20 g of water at 0° C will converted to 10° C water.

∴ heat given is

Q₃ = m_wS_w∆T              

Specific heat of water (S_w) = 1 cal/gram ° C

ΔT = temperature change = 10° - 0° C = 10° C

∴ Q₃ = 20 × 1 × 10              

Q₃ = 200 cal

Total heat Q = Q₁+ Q₂+ Q₃

∴ Q = 50 + 800 + 200

Q = 1050 cal

The correct answer is Lime Water.

Key Points

• Limestone, chalk, and marble have calcium carbonate.
• Lime water has lime or citrus.
• It does not have calcium carbonate.
• Limewater is calcium hydroxide, Ca(OH)₂.
• It is soluble (only sparsely) in water at room temperature.
• Excessive Calcium Hydroxide when added, it results in a milky solution.
• Thus the answer will be lime water.

Soaps and detergent act like emulsifiers and surfactants respectively, while cleaning clothes. Soaps use the principle of surface tension to clean surfaces.

• Surface tension is that property of water through which it acts like an elastic membrane.
• When soap is added, it lowers the surface tension of water.
• This helps soaps in cleaning the surface due to reduced intermolecular forces in water, through which hydrophilic and hydrophobic ends can work.
• Viscosity is the resistance offered to deformation at a given rate by a liquid.
• Flotation is a method widely used in Wastewater Treatment.

Tin is a Pure Substance.

• A Pure substance is something having a homogeneous composition.
• Other examples of pure substances include - Diamond, Sulfur, Iron, Steel, and Water.
• Sea Water, Soil, and Air are mixtures.
• A mixture is a combination of two or more pure substances in which each pure substance retains its individual chemical properties.
• Tin can be mixed with other elements like copper to make Bronze. (An alloy)

Dry ice is the solid form/state of carbon dioxide (CO₂).

• It is a molecule that consists of a single carbon atom bonded to two other oxygen atoms.
• Dry ice is non-flammable and colorless.
• When dissolved in water, dry ice can lower the pH of a solution, and form carbonic acid.
• Applications - Food preservation, Airline Shipping, Freeze Branding.

Movement from a solvent molecule from a diluted solution/less concentrated solution to a more concentrated solution through a permeable membrane is called osmosis.

• Dispersion involves a system in which the distributed particles disperse from one material to another material in a continuous phase.
• Diffusion is the movement of particles or ions from an area of higher concentration to an area of lower concentration.
• Absorption is the act of assimilating. Example - Absorption of drugs in the bloodstream.

The correct answer is Connective tissue.

• Blood is a type of connective tissue.

Key Points

• Blood is a fluid connective tissue containing plasma, red blood cells (RBC), white blood cells (WBC), and platelets.
• It is the main circulating fluid that helps in the transport of various substances.
• Connective tissues are most abundant and widely distributed in the body of complex animals.
• They are named connective tissues because of their special function of linking and supporting other tissues/organs of the body.
• They range from soft connective tissues to specialized types, which include cartilage, bone, adipose, and blood.

The correct answer is Proteins.

Key Points

• Due to the presence of a nucleus and ribosomes, mitochondria are able to produce their own proteins.
• Mitochondria is is a double-layered cell organelle, in which the outer layer is porous and the inner layer is folded upon itself is known to be cristae.
• The number of mitochondria in a single cell may be up to 50 to 5000.
• The inner lumen of mitochondria contains ribosome phosphate particles and DNA molecules.
• It has the potential to synthesize its own protein and oxidation of carbohydrates and fats are taken place with the help of enzymes in mitochondria.
• This energy is stored in the form of ATP ( Adenosine Triphosphate ) so, these are known as the "Powerhouse of the cell".

Important Points

• Ribosomes are first observed under the electron microscope by George Palade.
• They are composed of ribonucleic acid and protein and are not surrounded by any membrane.
• They are the site of protein synthesis.
• There are two types of ribosome
• Eukaryotic ribosomes-  80s
• Prokaryotic ribosomes-  70s​
• S = Svedberg unit or sedimentation rate.
• It indirectly is a measure of density and size.

Additional Information

• Chloroplasts - They are disc-shaped organelles that are found in the cytosol of a cell. Chloroplasts are found in algae and plants and are responsible for capturing light to make sugar through photosynthesis.
• Nucleus - They are membrane-bound organelle that is found in Eukaryotic Cells.