NDA General Ability Test 19 April 2015 Official Paper (Previous Year Paper)

The correct answer is option 1) i.e. A.

Key Points

• Let's have a look at the phrases given below:

• ​Start/stop + V1 + ing + something

• ​The phrase is used in its original form without any alterations.

• For example:

• ​My father has started to go to yoga classes lately. 

• ​My father has started going to yoga classes lately.

• ​Hence in the 1st part of the question, 'stop making' will be used instead of 'stop to make'.

Correct Sentence: *"*Unless you stop making noise at once, I will have no option but to bring the matter to the attention of the police."

The correct answer is option 1) i.e. A.

Explanation:

• Let's have a look at the phrases given below:
• ​Can/could not help + V1 + ing
• Can/could not help + but + V1
• ​Both of the phrases mean to have a compulsion to do something that is too strong to ignore or avoid.**
• For example:
• ​My mom can't help meddling in my life, even though I'm 26 years old.
• ​My mom can't help but meddle in my life, even though I'm 26 years old.
• Hence in the 1st part in the question, 'couldn't help but' will be used instead of 'couldn't but help'.

Correct Sentence: *"*He couldn't help but shed tears at the plight of the villagers rendered homeless by a devastating cyclone."

The part which contains error is C

Key Points

• After reading the sentence we can easily comprehend that the candidate was confused as a result of which none could clearly understand his principles and promises.
• Here the use of 'either-or' makes the sentence contextually wrong, it is used in a sentence in the affirmative sense when referring to a choice between two possibilities.
• Thus 'neither-nor should be used in a sentence in the negative sense when you want to say that two or more things are not true.
  

Correct Sentence: Since it was his first election campaign, the candidate was confused; none could clearly understand neither the principles he stood for nor the benefits he promised.

The correct answer is option 3) i.e. C.

Explanation:

• We use the term 'more' when we compare two or more persons/things.
• In the 3rd part of the given question, 'more' is used but there is no comparison made with any entity whatsoever.
• Hence we will omit 'more' from the 3rd part as the given sentence simply states that the American poets and philosophers were influenced by Indian philosophy, in particular by Upanishadic philosophy.

Correct Sentence: *"*It is an established fact that the transcendental American poets and philosophers, who lived in the latter half of the nineteenth century, were influenced by Indian philosophy, in particular by Upanishadic Philosophy."

The correct answer is option 2) i.e. B.

Key Points 

• Some conjunctions such as: 'No sooner...than', 'Hardly/scarcely...when', are used in a pair.

• For example :

• Hardly had I left the cinema hall than I saw the actor himself.  

• Hardly had I left the cinema hall when I saw the actor himself.  

​

• Hence in the 2nd part of the sentence, 'than' will be used instead of 'when'.​

Correct Sentence: "No sooner did I open the door than the rain, heavy and stormy, rushed in making us shiver from head to foot."

The correct answer is option 2) i.e. B.

Explanation:

• Whenever 'enter' is used in the context of motion, we never use 'into' after 'enter' as it makes the sentence superfluous.​

• For example:

• ​Jay entered into the hall with his wife.

• Jay entered the hall with his wife.

• Hence in the 2nd part in question, we will remove 'into' used after 'entered'.

​​

• 'Enter into' is used when any agreement/alliance is talked about in a sentence.
• For example:
• ​Karan entered into an alliance with a regional party.

​​

Correct Sentence: "After opening the door we entered the room next to the kitchen."

The correct answer is option 2) i.e. B.

Explanation:

• The structure 'is/am/are/was/were + V₃' is used when a passive form of voice is required.

• For example:

• The game was playing between India and Sri Lanka at Adelaide. 

• The game was played between India and Sri Lanka at Adelaide.

• Since the given sentence is in an active voice form, we will omit 'was' in the 2nd part of the given sentence.

Correct Sentence: *"*When the dentist came in my tooth stopped aching out of fear that I might lose my tooth."

The correct answer is option 2) i.e. B.

Explanation:

• The verb 'ensure' is not followed by any preposition.

• For example:

• The airline is taking steps to ensure of safety on its aircraft. 

• The airline is taking steps to ensure safety on its aircraft.

• We will omit 'for' in the 2nd part of the given sentence to make the sentence error-free.

Correct Sentence: *"*Emphasis on equality of life ensures the health and happiness of every individual."

The correct answer is option 2) i.e. B.

Explanation:

• Let's understand the difference between the two words given below:

• ​Wait- stay where one is or delay action until a particular time or event.

• Await- wait for (an event).

• ​The verb 'await' is never followed by 'for' as it makes the phrase superfluous.

• For example:

• Theresa was awaiting for her lover. 

• Theresa was awaiting her lover.

• We will omit 'for' in the 2nd part of the given sentence to make the sentence error-free.

• Though we may use 'for' with the verb 'wait' as it is grammatically correct.

Correct Sentence: "The students were awaiting the arrival of the chief guest."

The correct answer is option 3) i.e. C.

Explanation:

• If the statement is negative, the question tag must be positive and vice versa.

• We have to use the pronoun, according to the subject, in the question tag.

• The sentence and the question tag must be in the same tense.

• For example :

• They have eaten popcorn, Isn't it?  

• They have eaten popcorn, haven't they?  

​​​​​

• ​Hence in the 3rd part of the sentence, 'Won't you?' will be used as per the rule given above.

Correct Sentence: "You will come to my party tomorrow, won't you ?"

The correct answer is option 3) i.e. C.

Explanation:

• The word 'about', mentioned in the 3rd part of the given sentence, is misplaced and alters the intended meaning.
• The sentence wants to convey that the subject has read some stories about space and now wants to travel the moon.
• To maintain continuity and desired structure, we will omit 'about' from the 3rd part of the given sentence.

Correct Sentence: *"*Having read a number of stories about space travel, his dream now is to visit the moon."

The correct answer is option 1) i.e. A.

Explanation:

• The structure 'is/am/are/was/were + V3' is used when a passive form of voice is required.

• For example:

• The game was playing between India and Sri Lanka at Adelaide. 

• The game was played between India and Sri Lanka at Adelaide.

• Since the given sentence is in a passive voice form, we will insert 'was'  after the word 'meeting' in the 1st part of the given sentence.

Correct Sentence: *"*The meeting was adjourned abruptly by the Chairman after about three hours of deliberation."

The correct answer is option 3) i.e. C.

Explanation:

• 'None/one of' is used when we have to choose between more than two options.

• 'Neither/either of' is used when we have to choose between the two options.

• Also if a choice is being made out of many things, the verb will conform to the former subject.

• For example :

• Either of the students are not present today.  

• One of the students is not present today.  

​​​​​

• Since the first subject i.e 'Not one' is a singular noun, 'was' will be used instead of 'were'.

​

Correct Sentence: "Not one* of the hundreds of striking workers was allowed to go near the factory."*

The correct answer is option 3) i.e. C.

Explanation:

• Conditional sentences are statements discussing known factors or hypothetical situations and their consequences.

• One of the structures is mentioned below:

• This particular type is followed when something didn't happen as a certain condition wasn't fulfilled.

• If + Past perfect, Subject + Would have + V3 + Object.

• For example:

• If I had noticed you, I would had call you. 

• If I had noticed you, I would have called you. 

​

• Hence in the 3rd part of the given sentence, 'would have' will be used instead of 'will have'.

Correct Sentence: " If I had known this earlier I would have helped him."

The correct answer is option 1) i.e. A.

Explanation:

• There are some verbs that are followed by some fixed prepositions. Some of them are given below:

• Accused of, Afraid of, Conform to, Devoid of, Gaze/look at, Insist on, Versed in, Ward off, etc.

• For example:

• ​One should conform with the rules of the game while playing. 

• One should conform to the rules of the game while playing.

• Hence the verb 'accused' will be followed by the preposition 'of'.

​​

Correct Sentence: "Mr. Smith was accused of murder but the court found him not guilty and acquitted him."

The correct answer is option 2) i.e. B.

Explanation: ​

• Let's have a look at the meanings of the given phrases:
• By far- by a great amount.
• Few and far between- not very many or not appearing very frequently
• By and large- on the whole; everything considered.
• By and by- after a short period.
• In the underlined part, we need an expression that takes into account everything, hence 'by and large' is an apt choice here.

Correct Sentence: "Although India is still by and large a poor country, it can become rich if its natural and human resources are fully utilized."

The correct answer is option 3) i.e. C.

Explanation:

• If 'the' is used with a comparative degree and two degrees are shown to be directly/inversely proportional to each other, the other degree will also be comparative. For example:

• The higher you climb, the most difficult it will be to breathe. 

• The higher you climb, the more difficult it will be to breathe. 

• Hence as per the rule given above, 3rd option will be the most appropriate choice here.

Correct Sentence: "The more they earn, the more they spend."

The correct answer is option 2) i.e. B.

Key Points

• The structure 'is/am/are/was/were + V3' is used when a passive form of voice is required.

• For example:

• The game was playing between India and Sri Lanka at Adelaide. 

• The game was played between India and Sri Lanka at Adelaide.

• Since the given sentence is in a passive voice form, we will use 'are well formulated' in the underlined part of the given sentence.

Correct Sentence: "**But in all these cases conversion from one scale to another is easy because scales are well-formulated."

The correct answer is option 1) i.e. A.

Explanation:

• The past continuous tense is used to show that an ongoing past action was happening at a specific moment of interruption, or that two ongoing actions were happening at the same time.
• For example:
• ​You were playing when she called.
• Since the given sentence mentions a past event that was in progress, 'was sitting' will be the most appropriate choice in the underlined part.

Correct Sentence: *"*Five years ago on this date, I was sitting in a small Japanese car, driving across Poland towards Berlin."

The correct answer is option 2) i.e. B.

Key Points

• An adverb is a word or phrase that modifies or qualifies an adjective, verb, or other adverb or a word group.

• Hardly is an adverb which means scarcely (used to qualify a statement by saying that it is true to an insignificant degree).

• 'Hardly' is a negative word and doesn't take any negative word after it as it will make the sentence superfluous.

• **For example:​

• He hardly does no work. 

• He hardly does any work.

• Hence 2nd option will be the most appropriate choice here as per the rule given above.

Correct Sentence: "The old man felled some trees in the garden with hardly any effort at all."

The correct answer is to take her word for it

Key Points

• There is an expression which is used in its original form without any alterations:
• ​Take someone’s word for it- to believe that what someone is saying is true.
• ​For example:
• ​If she says she’s sick, you have to take her word for it.
• ​Hence option 3 will be the most appropriate choice here.

Correct Sentence: "She says she's already paid me back, but I can't remember, so I'll have to take her word for it."

The correct answer is option 1) i.e. A.

Key Points

• Let's have a look at the phrase given below:
• ​Hell bent on- to be extremely determined to do something, without considering the risks or possible dangerous results.
• ​The given phrase is used as the way it is, without any alterations.
• For example:
• ​He was hell-bent on taking revenge.
• Hence in the underlined part, 'hell bent on getting' is the most appropriate choice.

Correct Sentence: “The workers are hell-bent on getting what is due to them."

The correct answer is No improvement

Key Points

• Let's have a look at the phrasal verb given below:
• ​Warn against- to advise someone not to do something because it may have dangerous or unpleasant results.
• ​The given phrase is used as the way it is, without any alterations.
• For example:
• ​Her financial adviser warned her against such a risky investment.
• Hence in the underlined part, 'against committing' is the most appropriate choice.

Correct Sentence: “You are warned against committing the same mistake again."

The correct answer is option 3) i.e. C.

Key Points

• Since the given sentence talks about 'Indian children' in general and not any specific category, the article 'the' will not be used.
• Hence options 1 and 2 are eliminated. As 'to' infinitive is used after the underlined part, we cannot use 'that' with 'all Indian children'.
• This brings us to the correct option i.e 3rd option.

Correct Sentence: *"*While we would like all Indian children to go to school, we need to ponder why they do not."

The correct answer is 'For these reasons'.

Key Points

• 'For these reasons' is the suitable phrase to express the cause or basis for a decision or viewpoint, in this case, being in favor of universal compulsory education.
• It accurately conveys the connection between the reasons previously stated and the conclusion drawn, making the sentence clearer and more appropriate.
• English sentences generally use the form "For these reasons, [conclusion]" to express reasoned conclusions or actions.

Therefore, the correct answer is 'Option 2'.

Additional Information

• Option 1 'Out of these reasons': This is not a commonly used English phrase to indicate causality or reasoning.
• Option 3 'By these reasons': Similarly, 'By these reasons' is not used in standard English to express the idea the sentence intends to convey.
• Option 4 'No improvement': The initial sentence can indeed be improved, making this option incorrect.

The correct answer is option 2) i.e. B.

Explanation:

• Let's have a look at the phrasal verb given below:
• ​Join in- to take part in something that a group of people is doing or that someone else does.
• ​The given phrase is used as the way it is, without any alterations.
• For example:
• ​He stared at them without joining in the conversation.
• Hence in the underlined part, 'in crushing' is the most appropriate choice.

Correct Sentence: *"*When it was feared that the serfs might go too far and gain their freedom from serfdom, the Protestant leaders joined the princes in crushing them."

The correct answer is option 4) i.e. D.

Explanation:

• The present perfect tense is used to show that an action has taken place once or many times before now. It is most frequently used to talk about experiences or changes that have taken place.
• For example:
• ​He has achieved so much in his favorite subject.
• Since the given sentence talks about the happenings that have taken place after the French Revolution, present perfect tense will serve the purpose in the latter part. Hence, 'much has happened' is the most appropriate choice here.

Correct Sentence: "**In India, today many of our intellectuals still talk in terms of the French Revolution and the Rights of Man, not appreciating that much has happened since then."

The correct answer is option 3) i.e. C.

Key Points

• 'Ought to' is used to indicate duty or correctness, typically when criticizing someone's actions.
• For example:
• ​They ought to respect the law.
• Whereas ​'have to' is used to express certainty, necessity, and obligation.
• For example:
• ​I have to go to Vermont tomorrow.
• Since the given statement is more similar to a form of advice, 'ought to' is the most appropriate choice here.

Correct Sentence: *"*Taxpayers ought to be conscious of their privileges."

The correct answer is option 1) i.e. A.

Key Points

Conditional sentences are statements discussing known factors or hypothetical situations and their consequences.

• One of the structures is mentioned below:

• This particular type is followed when something didn't happen as a certain condition wasn't fulfilled.

• If + Past perfect, Subject + Would have + V₃ + Object.**

• For example:

• If I had noticed you, I would had call you. 

• If I had noticed you, I would have called you. 

​

• Hence in the underlined part of the given sentence, 'had known' will be used instead of 'knew'.

Correct Sentence: "I would have waited for you at the station if I had known that you would come."

The correct answer is option 2) i.e. B.

Explanation:

• Let's have a look at the meanings of the given words:
• Penetrate- go into or through (something), especially with force or effort.
• Perpetuate- make something continue indefinitely.
• Perpetrate- carry out or commit (a harmful, illegal, or immoral action).
• Precipitate- cause (an event or situation, typically one that is undesirable) to happen suddenly, unexpectedly, or prematurely.
• ​Of the given options, 'perpetrate' i.e 2nd option is the most appropriate as per the context of the sentence.

Correct Sentence: "No one could explain how a calm and balanced person like him could perpetrate such a mindless act on his friends."

The correct answer is option 4) i.e D.

Explanation:

• Since the introductory part is already there, Q will be the 1st statement as it takes the story forward by providing more information about the glass tube.
• As we can see there is only one option with Q as the 1st statement i.e 4th option.
• Hence the correct order will be: Q-S-P-R.

The correct answer is option 1) i.e A.

Explanation:

• Since the introductory part is already there, Q will be the 1st statement as it takes the story forward by talking about other attributes like love and friendship.
• The next statement will be P as contradicts the last statement and states 'hope' as 'everlasting'.
• Now the statement P must be followed by S as it tells the source from which man derives 'hope'.
• And the concluding statement will be S.
• Hence the correct order will be: Q-P-R-S.

The correct answer is option 2) i.e B.

Explanation:

• Since the introductory part is already there, R will be the 1st statement as it takes the story forward by talking about the place where Mr. Sherlock Holmes and Doctor Watson were staying.
• The next statement will be P as tells us about the visit by someone who was known to them.
• Now the statement P must be followed by S as it narrates how Mr. Soames looked like.
• And the concluding statement will be Q.
• Hence the correct order will be: R-P-S-Q.

The correct answer is option 2) i.e B.

Explanation:

• Since the introductory part is already there, Q will be the 1st statement as it tells us more about the idea of exhaustion of sources of power.
• The next statement will be P as it further states that the sources are exhaustible.
• Now the statement P must be followed by R as it makes us explore other sources of power as well.
• And the concluding statement will be S.
• Hence the correct order will be: Q-P-R-S.

The correct answer is option 3) i.e C.

Explanation:

• Since the introductory part is already there, Q will be the 1st statement as it furthers the statement in S1.
• The next statement will be R as it takes us to another aspect of body movement mentioned as 'breathing'.
• Now the statement R must be followed by P as it talks about the idea of catalyst needed for an activity.
• And the concluding statement will be S.
• Hence the correct order will be: Q-R-P-S.

The correct answer is option 3) i.e C.

Explanation:

• Since the introductory part is already there, R will be the 1st statement as it gives us the idea about how an American thinks of history.
• The next statement will be P as it states the consequences of human efforts in the future.
• Now the statement P must be followed by Q as it tells us about the pragmatic aspect of an American.
• And the concluding statement will be S.
• Hence the correct order will be: R-P-Q-S.

The correct answer is option 2) i.e. B.

Explanation:

• Let's have a look at the meanings of the given words:
• Felt- be aware of (a person or object) through touching or being touched.
• Occurred- (of a thought or idea) come into the mind of.
• Happened- be experienced by (someone).
• In the given sentence, the subject thinks that he is being followed by someone.
• Hence the most appropriate of the given options is 'occurred' i.e 2nd option.

The correct answer is option 1) i.e. A.

Explanation:

• Let's have a look at the meanings of the given words:
• Followed- go or come after (a person or thing proceeding ahead); move or travel behind.
• Shot- kill or wound (a person or animal) with a bullet or arrow.
• Looked- direct one's gaze in a specified direction.
• In the given sentence, it is evident from the former blank that the subject has a notion of being pursued by someone.
• Hence the most appropriate of the given options is 'followed' i.e 1st option.

The correct answer is option 3) i.e. C.

Explanation:

• Let's have a look at the meanings of the given words:
• ​Reason- a cause, explanation, or justification for an action or event.
• Cause-*** a person or thing that gives rise to an action, phenomenon, or condition.*
• Evidence-*** the available body of facts or information indicating whether a belief or proposition is true or valid.*
• In the given sentence, the subject wants some sort of corroboration to confirm the fact that he is being pursued by someone.
• Hence the most appropriate of the given options is 'evidence' i.e 3rd option.

The correct answer is option 2) i.e. B.

Explanation:

• Let's have a look at the meanings of the given words:
• ​Weight- a measure of the heaviness of an object; the amount anything weighs.
• Sound- it is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid.
• Hurting- cause pain or injury to.
• In the given sentence, the term 'footsteps' given just after the blank (40), suggests that the subject heard a sound of footsteps.
• Hence the most appropriate of the given options is 'sound' i.e 2nd option.

The correct answer is option 2) i.e. B.

Explanation:

• Let's have a look at the phrasal verb given below:
• ​Walk down- to travel by foot along the lane.
• ​The given phrase is used as the way it is, without any alterations.
• For example:
• ​I was walking down the street when came across an old friend.
• Hence the most appropriate of the given options is 'down' i.e 2nd option.

The correct answer is option 1) i.e. A.

Explanation:

• Let's have a look at the phrasal verb given below:
• ​Crowded with- filled with many or too many people or things.
• ​The given phrase is used as the way it is, without any alterations.
• 'Crowded by' is used sometimes but 'crowded with' is more appropriate grammatically.
• For example:
• ​The restaurant was crowded with people.
• Hence the most appropriate of the given options is 'with' i.e 1st option.

The correct answer is 'relieved of his job'.

Key Points

• The given word 'fired' means to remove an employee from a job. (कर्मचारी को नौकरी से निकाल देना)
• ​Let's see the meaning of other given options:-
• 'Relieved of his job' means to release someone from duty. (किसी को कर्तव्य से मुक्त करना)
• 'Scolded' means to speak angrily to somebody because he or she has done something bad or wrong. (ख़राब या ग़लत काम के लिए किसी को डाँटना; फटकारना)
• 'Rebuked' means to speak angrily to somebody because he or she has done something wrong. (ग़लती पर डाँटना-फटकारना)
• 'Attacked' means to damage or harm somebody or something. (हानि पहुँचाना)
  

Hence, the correct answer is option 1.

Additional Information

• The synonyms of the word 'fired' are "relieved, released, removed".
• The antonyms of the word 'fired' are "employed, hired, retained".
• Example of 'fired' in a sentence:
• He got fired because he was lazy.

The correct answer is option 3) i.e. C.

 Key Points

• The given word 'obliterate' means destroy utterly; wipe out. (पूरी तरह से नष्ट; मिटा दो)
• Let's have a look at the meanings of the given words:
• Demolish- pull or knock down (a building). (खींचो या खटखटाओ (एक इमारत))
• Extinguish- cause (fire or light) to cease to burn or shine. (कारण (आग या प्रकाश) जलना या चमकना बंद करना)
• Erase- remove all traces of; destroy or obliterate. (के सभी निशान हटा दें; नष्ट करना या मिटा देना)
• Change- make or become different. (बनाना या अलग होना)
• The most appropriate synonym of the given options is 'erase' i.e 3rd option.

The correct answer is option 3) i.e. C.

Explanation:

• The given word 'ineffable' means too great or extreme to be expressed or described in words.
• Let's have a look at the meanings of the given expressions:
• That which cannot be rubbed out- Indelible.
• Incapable of being understood- Unitellegible, unfathomable.
• Too powerful to be defeated- Invincible, insuperable.
• The most appropriate synonym of the given options is 'too great or extreme to be expressed or described in words.' i.e 3rd option.

The correct answer is option 3) i.e. C.

Explanation:

• The given word 'edifying' means p**roviding moral or intellectual instruction.
• Let's have a look at the meanings of the given words:
• Tedious- too long, slow, or dull; tiresome or monotonous.
• Instructive- useful and informative.
• Exciting- causing great enthusiasm and eagerness.
• The most appropriate synonym of the given options is 'Instructive' i.e 3rd option.

The correct answer is option 1) i.e. A.

Key Points:- 

• The given word 'Shabbily' means wearing worn clothes or having a slovenly or unkempt appearance. (पहने हुए कपड़े पहनना या एक गंदे या बेदाग दिखने वाला)
• Let's have a look at the meanings of the given words:
• Decently- in a way that conforms to generally accepted standards of respectable or moral behavior. (एक  तरह से जो सम्मानजनक या नैतिक व्यवहार के आम तौर पर स्वीकृत मानकों के अनुरूप हो)
• Beautifully- in a way that pleases the senses or mind aesthetically. (एक तरह से जो इंद्रियों या मन को सौंदर्य से प्रसन्न करता है)
• Extravagantly- with a lack of restraint in spending money or using resources. (पैसे खर्च करने या संसाधनों का उपयोग करने में संयम की कमी के साथ)
• Scantily- in a way that is small or insufficient in quantity or amount. (एक प्रकार से जो मात्रा या मात्रा में छोटा या अपर्याप्त हो)
• The most appropriate antonym of the given options is 'Decently' i.e 1st option.

The correct answer is option 3) i.e. C.

Explanation:

• The given word 'Urbane' means of a person, especially a man) courteous and refined in manner. (एक व्यक्ति, विशेष रूप से एक आदमी) विनम्र और तरीके से परिष्कृत)
• Let's have a look at the meanings of the given words:
• Civilised*-* polite and behave in a calm and reasonable way. (विनम्र और शांत और उचित तरीके से व्यवहार करें।)
• Slow- 

moving or operating, or designed to do so, only at a low speed; not quick or fast. (चलती या संचालन, या ऐसा करने के लिए डिज़ाइन किया गया, केवल कम गति पर; जल्दी या तेज नहीं)

• Rude- offensively impolite or bad-mannered. (आक्रामक रूप से अभद्र या बुरे आचरण वाला)
• Foolish- lacking good sense or judgement; unwise. (अच्छी समझ या निर्णय की कमी; मूर्ख)
• The most appropriate antonym of the given options is 'Rude' i.e 3rd option.

The correct answer is option 2) i.e. B.

Explanation:

• The given word 'thrifty' means using money and other resources carefully and not wastefully.
• Let's have a look at the meanings of the given words:
• Expensive- costing a lot of money.
• Extravagant- lacking restraint in spending money or using resources.
• Economical- giving good value or return in relation to the money, time, or effort expended.
• Good- to be desired or approved of.
• The most appropriate antonym of the given options is 'Extravagant' i.e 2nd option.

The correct answer is option 3) i.e. C.

Explanation:

• The given word 'pride' means a feeling or deep pleasure or satisfaction derived from one's own achievements.
• Let's have a look at the meanings of the given words:
• Lowliness- low in growth or position.​
• Submission- the action of accepting or yielding to a superior force or to the will or authority of another person.
• Humility- the quality of having a modest or low view of one's importance.
• Obedience- compliance w**ith an order, request, or law or submission to another's authority.
• The most appropriate antonym of the given options is 'Humility' i.e 3rd option.

The correct answer is Option 2.

• The growth of plants is smooth with a complete fertilizer. Hence statement I is correct
• Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, etc. are the essential elements for plant growth.
• Plants cannot absorb these elements directly from the air even though elements like Nitrogen is available in a large amount (some of the plants in association with N₂-fixing bacteria, especially roots of legumes, can fix this atmospheric nitrogen into biologically usable forms).
• Some of these elements will deplete in the soil very quickly and hence plants can absorb it in the form of complete fertilizers.
• A complete fertilizer always contains N, P, K. Hence statement II is correct.
• A complete fertilizer is a fertilizer that contains the three main plant nutrients: Nitrogen (N), Phosphorus (P), and Potassium (K).
• Potassium helps plants to develop strong stems and growing fast.
• Nitrogen helps plants for the growth of leaf and green color.
• Phosphorous helps plants to form new roots, make seeds, fruit, and flowers.
• There are six essential nutrients namely nitrogen, phosphorus, potassium, magnesium, sulfur, and calcium are essential for the growth of plants. Hence Statement II is not the correct explanation of Statement I.

The correct answer is Option 1.

• The granules of modern gunpowder (also called black powder) are typically coated with Graphite, hence statement I is correct.
• Modern gun powder consists of Potassium nitrate, Charcoal and Sulfur in 75%, 15%, and 10% respectively.
• Each of these components plays an important role in the combustion of gunpowder.
• Use of Graphite in the form of a coating reduces moisture absorption, which could prevent gunpowder from igniting.
• Gunpowder has been widely used as a propellant in firearms, rockets, and fireworks.
• Graphite prevents the build-up of electrostatic charge. Hence statement II is correct.
• Graphite is a crystalline form of the element carbon with hexagonal structure.
• It is a good conductor of heat and electricity.
• Graphite lubricates the particles and also confirm the powder electricity is conductive enough to avoid accidental discharges.
• Used in electronic products such as electrodes, batteries, and solar panels.
• To minimize the chance of accidental ignition by static electricity, the granules of modern black powder are typically coated with graphite, which prevents the build-up of electrostatic charge. Hence Statement II is the correct explanation of Statement I.

The correct answer is Option 1.

• Colour of Nitrogen dioxide changes to colourless at low temperature. Hence statement I is correct.
• Nitrogen dioxide is one of several nitrogen oxides with chemical formula NO₂.
• At higher temperatures, it is a reddish-brown gas.
• As the temperature decreases (below -11.2 °C), it converts to the colorless Dinitrogen tetroxide(N₂O₄).
• NO₂ is used as an intermediate in the manufacturing of nitric acid.
• NO₂ exists in equilibrium with the colourless gas Dinitrogen tetroxide (N₂O₄).
• At low temperature Nitrogen tetroxide (N₂O₄) is formed which is colourless.
• Dinitrogen tetroxide, commonly referred to as Nitrogen tetroxide.
• It is a useful reagent in chemical synthesis.
• As the temperature reduces below -11.2 °C, N₂O changes to N₂O_4, which is colourless in nature.
• Reddish-brown N₂O will change to colourless N₂O₄ in low temperature. Hence Statement II is the correct explanation of statement I.

The correct answer is Option 3.

• Diamond is very bright, hence statement I is correct.
• Diamond is a solid form of carbon.
• Diamond shows the highest hardness and thermal conductivity comparing to other natural material.
• Due to the high refractive index of diamond (2.417), a greater percentage of the incident light gets internally reflected several times before it emerges from the diamond, this makes the diamond bright.
• Diamond has a very high refractive index, nearly 2.417, hence the Statement II is false.

The correct answer is Option 3.

• Oxygen gas is easily produced at a faster rate by heating a mixture of Potassium Chlorate and Manganese dioxide than heating Potassium chlorate alone, hence Statement I is true.
• When Potassium chlorate (KClO₃) is heated in the presence of a Manganese dioxide catalyst, it breaks down and form Potassium chloride and oxygen gas.
• $KClO_3 \xrightarrow{\text{MnO2}} 2 KCl+3O_2$
• Oxygen gas is easily produced at a faster rate in the above reaction than heating Potassium chlorate alone.
• Manganese dioxide will act as a positive catalyst here.
• A catalyst is a substance that causes an increase in the rate of a chemical reaction without being used up in the reaction.
• If catalyst increases the rate of a reaction then the catalyst is known as the positive catalyst.
• Manganese dioxide acts as a positive catalyst, hence Statement II is false.

CONCEPT:

• The acceleration achieved by any object due to the gravitational force of attraction by any planet is called acceleration due to gravity by the earth.
• As each planet has different mass and radius so the acceleration due to gravity will be different for different planet.

Acceleration due to gravity of earth having mass M on the surface of the earth is given by:

$g = \frac{{GM}}{{{R^2}}}$

Acceleration due to gravity at height (h) above the earth’s surface is given by:

$Acceleration;due;to;gravity;at;height;\left( {g'} \right) = \frac{{g;}}{{{{\left( {1 + \frac{h}{R}} \right)}^2}}}$

Where G is Universal gravitational constant, R is radius of the earth and h is height

Weight (W) = m g

EXPLANATION:

Weight on earth’s surface is given by:

W = m g

Weight on the hill top of height h is given by:

$W' = m;g' = \frac{{m;g;}}{{{{\left( {1 + \frac{h}{R}} \right)}^2}}}$

W > W’

• The acceleration due to gravity above the earth’s surface decreases with height and hence the weight of the body is less at the hill top than at the earth’s surface. Thus statement II is correct explanation for statement I. So option 1 is correct.

CONCEPT:

• Heat Transfer: Heat is transferred from one place to another in substance due to temperature difference.

• Evaporation: In this process the liquid form a substance tends to convert in the gaseous phase on the uppermost surface due to heat and pressure.
• Condensation: In this process the gaseous phase of an object tends to convert into liquid form due to pressure and temperature.

EXPLANATION:

• When we increased the surface area then more liquid will be exposed to air at a given time, and therefore, more water can evaporate in given period of time. So cloths will dry up soon.
• The statement II is correct explanation for statement I. So option 1 is correct.

CONCEPT:

• Laws of reflection: The angle of reflection equals the angle of incidence.
• The incident ray, the reflected ray and the normal lie in the same plane.
• When light rays strikes on a smooth plane surface then the reflection is called regular reflection.
• When light reflects at many angles after the incidence on the surface, such a reflection is called as diffuse reflection.
• Light rays are not parallel to each other after irregular reflection, but they obeys laws of reflection at each point of reflection.

EXPLANATION:

• In case of room, due to diffused reflection, the light gets spread in whole room and the room gets light. So statement I is correct.
• The laws of reflection are followed by both- regular reflection as well as diffused reflection. So statement II is wrong. Hence option 3 is correct.

Concept:

• The sound waves propagate through air in different frequency, among this human ears can only sense sound of bandwidth 20 Hz-20 kHz.
• Sound waves with frequency greater than audible waves is known as Ultrasonic waves.
• The wavelength of this wave can be defined as displacement made when a wave complete its one oscillation
• And relation between wavelength (λ), frequency (n) and velocity (v) can be given as

v = n × λ

Calculation:

Given that,

Frequency (n) = 3 × 10⁵ Hz

Velocity of sound in air = 300 m/s

Velocity of sound in medium = 10 × 300 m/s

Now Wavelength of ultrasonic wave can be calculated using relation

$v; = ;n \times \lambda \Rightarrow \lambda = \frac{v}{n} = \frac{{3000}}{{3 \times {{10}^5}}} = 0.01;m = 1;cm$

CONCEPT:

Acceleration Due to Gravity:

• The force of attraction exerted by the earth on a body is called gravitational pull or gravity.
• The acceleration produced in the motion of a body under the effect of gravity is called acceleration due to gravity, it is denoted by g.
• If g is the acceleration due to gravity, then

$g = \frac{{GM}}{{{R^2}}}$

Where G = universal gravitational constant, M = mass of the earth, and R = radius of the earth.

• Error in the division of quantities: Suppose $x = \frac{a}{b}$
• The maximum fractional error in x is $\frac{{{\rm{\Delta }}x}}{x} = \frac{{{\rm{\Delta }}a}}{a} + \frac{{{\rm{\Delta }}b}}{b}$

CALCULATION:

Given that,

• Radius of the earth were to shrink by 1% → R₁ = R and R₂ = (100-1)% of R₂ = 0.99×R
• its mass remains the same → m = m₁ = m_2​

​

Acceleration due to gravity is before shrinking is

${g_1} = \frac{{G{m_1}}}{{R_1^2}} = \frac{{Gm}}{{R_1^2}}$        ---------(1)

Acceleration due to gravity is after shrinking is

${g_2} = \frac{{G{m_2}}}{{R_2^2}} = \frac{{Gm}}{{R_2^2}}$        ---------(2)

Divide equation 1 and 2, we get

$\frac{{{g_1}}}{{{g_2}}} = \frac{{\frac{{Gm}}{{R_1^2}}}}{{\frac{{Gm}}{{R_2^2}}}} = \frac{{R_2^2}}{{R_1^2}}$

$\frac{{{g_1}}}{{{g_2}}} = \frac{{R_2^2}}{{R_1^2}} = \frac{{{{0.99}^2} \times {R^2}}}{{{R^2}}} = {0.99^2}$

${g_1} = ;;0.98;{g_2}$ ⇒ g₂ = 1.02 g₁

Hence net change is gravitational Δg = g₂ - g₁ = (1.02 – 1) × g₁

Δg = 0.02 × g₁

⇒ Δg = 2% of g₁

Concept:

Force acting on a particle is directly proportional to its mass and the rate at which it is accelerating

Either F = ma

The relation between acceleration, displacement and time can be given using kinetic equation

s = ut +1/2 at²

Explanation:

• If a force acting on a particle is constant, the rate of its acceleration will be constant too
• Hence s = ut +1/2 at²
• Comparing this with parabola equation y = mx²
• The relation between displacement and time is quadratic when the acceleration is constant and therefore this curve is a parabola.
• The displacement-time graph consists of a curved-line whose gradient (slope) is increasing in time.

CONCEPT:

• The property of a liquid due to which its free surface tries to have the minimum surface area and behaves as if it were under tension somewhat like a stretched elastic membrane is called surface tension.
• The surface tension of a liquid is measured by the force acting per unit length on either side of an imaginary line drawn on the free surface of the liquid i.e.
• $Surface;tension = \frac{{Force}}{{length}}$

EXPLANATION:

• Surface tension is the result of the cohesive force among the liquid molecules, which always tries to make the surface area of the liquid droplet minimum.

• Hence due to exertion of surface tension by the molecules, water droplets always take a round shape whenever they are allowed to move freely and thus because of this we see a nearly spherical drop of rain.

• The oil and grease spots on clothes cannot be removed by pure water. On the other hand, when detergents (like soap) are added in water, the surface tension of water decreases. As a result of this, the wetting power of soap solution increases. Also the force of adhesion between soap solution and oil or grease on the clothes increases. Thus, oil, grease, and dirt particles get mixed with soap solution easily. Hence clothes are washed easily.

• The cohesive forces are responsible for surface tension between liquid molecules and wall of container hence along the wall of the surface liquid is more bound and rises above compared to centre this is known as capillary action which cause Capillary rise

• Hence only option 4 is not a result of surface tension among all.

• Surface tension of all lubricating oils and paints is kept low so that they spread over a large area.

The correct answer is Option 2, i.e A - 2, B - 4, C - 3, D - 1.

• Sodium hydroxide is also called caustic soda.
• Formula: NaOH
• Sodium hydroxide is highly soluble in water.
• Used in the manufacture of pulp and paper, drinking water, soaps, and detergents.
• Sodium hydroxide can be used for the detection of carbon monoxide poisoning.
• Calcium oxide is commonly known as quicklime.
• Formula: CaO.
• Calcium oxide is usually made by the thermal decomposition of materials.
• When quicklime is heated to 2400 °C, it emits an intense glow known as a limelight.
• ​Acetic acid also called Ethanoic acid.
• Formula: CH₃COOH.
• It is a weak acid.
• Vinegar is made up of acetic acid and water.
• Acetic acid is a chemical reagent for the production of chemical compounds.
• Hydrochloric acid is also called Muriatic acid.
• Formula: HCl.
• Hydrochloric acid was discovered by Jabir ibn Hayyan.
• It is a strong acidic.
• Used in the production of polyvinyl chloride for plastic.

Option 3 is NOT correct.

• Ratnagiri Bauxite mining area is located in Maharashtra. Hence, Option 3 is NOT correct.
• Ratnagiri is also famous for Silica sand Sea sand and ilmenite.
• Odisha is the largest Bauxite producing state in India.
• Jharkhand is called the mineral state of India.

The correct answer is Option 2, i.e A-1, B-3, C-4, D-2.

• The first paper mill in the country was set up at Serampore (Bengal) in 1812.
• Raw materials used in the paper industry are: Bamboo, Salai Wood, Sabai, Bagasse’s, Waste Paper & Rags.
• Major paper producing centres in Maharashtra: Pune, Nagpur, Balarshah,, Bhiwandi, Nandurbar, Kamptee, Vikroli, Chinchwad, Sangli, Kalyan, and Mumbai.
• Major paper producing centres in Madhya Pradesh: Rajgarh, Indore, Shahdol, Ratlam, Abdullaganj, Rewa, Vidisha, and Bhopal.
• Major paper producing centres in Andhra Pradesh: Pallancheru, Kakinada, Apidik, Bodhan, Rajahmundry, Sirpur, Tirupati, Kurnool, Khammam and, Srikakulam.
• Major paper producing centres in Karnataka: Bangalore, Mandya, Ramnagaram and Krishnarajsagar, Bhadravati, Nandangaud, Belagola, Munirabad and, Harihar.

The correct answer is Option 2 i.e 4 States.

Key Points

• The state of Telangana was officially formed on 2^nd June 2014 as the 29th state of India (Now there are only 28 states in India).
• Telangana shares its border with four other Indian states namely Maharashtra, Chhattisgarh, Andhra Pradesh, and Karnataka.
• A committee headed by former chief justice B. N. Srikrishna studied the formation of Telangana state.
• Telangana has three National Parks: Kasu Brahmananda Reddy National Park, Mahavir Harina Vanasthali National Park, and Mrugavani National Park.
• Indian tennis player Sania Mirza is the "brand ambassador" of Telangana.
• Current Governor of Telangana: Tamilisai Soundararajan.
• Current Chief Minister of Telangana: K. Chandrashekar Rao.

Mistake Points

• Telangana is surrounded by Maharashtra and Chhattisgarh in the North, Karnataka in the West and Andhra Pradesh in the South and East directions.
• Telangana Does not share a boundary with Odisha.

The correct answer is Option 1 i.e Metabolism.

• Metabolism is the chemical reaction in the body's cells that change food into energy.
• The metabolic processes help for growth and reproduction and allow living organisms to maintain their structures.
• The three main purposes of metabolism are:

1. Conversion of food to energy.
2. Conversion of food to building blocks for proteins, lipids, nucleic acids, and some carbohydrates.
3. Elimination of nitrogenous wastes.

• There are two categories of metabolism: Catabolism and Anabolism.

The correct answer is Carbohydrates, Proteins, Nucleic acids.

Key Points

• The four 'molecules of life' are proteins, carbohydrates, lipids, and nucleic acids. Each of the four entities is vital for every single organism on Earth.
• Proteins are the molecules found in cells.
• Proteins make up more than half of the weight of the cell other than water
• The protein is made of a long chain called amino acids.
• A carbohydrate molecule is made up of atoms of carbon, hydrogen, and oxygen.
• Nucleic acids consist of DNA and RNA.
• DNA (deoxyribonucleic acid) is a molecule that makes up the genetic material of a cell.
• RNA (ribonucleic acid) molecules are used to translate the information which is stored in DNA molecules and use the information to help build proteins.

Concept:

Force acting on a charged particle is given by Lorentz hence it is known as Lorentz force and it is expresses $\overrightarrow {F;} = ;q\left[ {\vec E - \vec v \times \vec B} \right];$

Net Force acting on charge = F

Force acting on the charge due to electric field = qE

Force acting on the charge due to magnetic field = qv×B or qvBsinθ

Where θ is the angle between the direction of the magnetic field and direction of motion of a particle

Explanation:

Given that if a charged particle (+q) is projected with certain velocity parallel to the magnetic which means that angle between the direction of magnetic field θ and direction of motion of a particle is 0°

And force acting Force acting on charge due to magnetic field = F_magnetic = +qvBsin(0°)

∴ F_magnetic = 0°

hence there is no net force acting on the charged particle (+) moving parallel to the magnetic field and because of this it will Continue its motion without any change

Concept:

Optical fibers are cylindrical solid glass material acting as waveguides made of two concentric layers of very pure glass.

The core (the interior layer) with refractive index n1 serves as the medium for light propagation, while the cladding (the exterior layer) has a lower refractive index n2 where n1 > n2 assuring that light rays are reflected to the core.

Since the cladding does not absorb any light from the core, the light wave can travel great distances.

Explanation:

• The working principle of optical fibers is Total Internal Reflection.
• Optical fiber mostly used for communication purposes with negligible loss of energy.
• The “Total Internal Reflection” of light is the boundary between transparent media of two different refractive indices.
• At present, Optical fiber cables are used for communication like sending images, voice messages, etc.
• The designing of this cable is done with Plastic or glass so that data can be transmitted effectively and quickly than other modes of communications.

Concept –

Kinetic energy (KE) –

• The energy possessed by a body by virtue of its motion is called kinetic energy.

$KE = \frac{1}{2}m{v^2}$

Where, m = mass of the body and v = velocity of the body

Potential energy (PE) –

• The energy possessed by a body by virtue of its position or configuration is called potential energy.

$PE = mgh$

Where, m = mass of the body, g = acceleration due to gravity and h = height of the body

Explanation –

As the swing rises, its kinetic energy is converted to potential energy. And as we know that potential energy is the energy possessed by a body by virtue of its position or configuration. Therefore, as the height increases, PE increases because PE is equal mgh.

According to law of conservation of energy, total energy of the system is always conserved i.e. E = KE + PE = constant. Hence, we can say that KE decreases and PE increases.

The correct option is 2 i.e. Potassium nitrate.

Key Points

• The gun powder is made of a mixture of Sulfur, Charcoal and Potassium nitrate.
• The sulfur and charcoal in the mixture act as fuels while the potassium nitrate is an oxidizer.
• Potassium nitrate is also known as Chile saltpetre.
• Magnesium sulfate is used to control low blood levels of Magnesium and to prevent toxaemia during pregnancy.
• Sodium stearate is a long chain of sodium salts of stearic acid.
• It is a white solid which is most commonly known as soap.
• Calcium sulphate is a calcium compound with the formula CaSO₄.
• It’s two common hydrates are Gypsum**(CaSO_4.2H₂O)** and Plaster of Paris (Caso4**.1/2**H2O).

Explanation: 

• When soap and detergent is added it breaks the cohesive forces between the liquid molecule
• The soap molecules form structures called micelles
• Oily dirt gets collected in the center of the micelle.
• Because of this the surface tension of liquid decreases when detergent or soap is added on a surface of the liquid which leads to the removal of dirt which is accumulated on the surface of the liquid.
• This is a reason why Soap micelles seem opaque can scatter light.

The correct option is 3 i.e. Sodium thiosulphate.

• Sodium thiosulphate​ and Ammonium thiosulfate are used as a fixer/developer in photography.
• Photographic fixation is the final process in developing the film.
• By fixation, the film or paper is insensitive to further action by light and fixes the image by removing the unexposed silver halides in the film.
• Sodium sulfate(Na₂SO₄) is used as a filler in detergents and to dry organic liquids.
• Sodium sulfide and Bleaching powder are used in the pulp and paper industry.
• sodium sulphide is also used in water treatment, textile industry.

The correct option is 2 i.e. Orographic rainfall.

• Rainshadow effect is associated with mountains and this kind of rainfall involving geological structures are known as Orographic rainfalls.
• Orographic rain is formed wherever moist air is forced to ascend a mountain barriers it is best developed on the windward slope.
• It is also known as relief rain.
• The leeward side gets less precipitation and hence remain dry. Ex- Vidarbha region of Maharashtra which is on the leeward side of Western Ghats.
• Cyclonic rainfall is associated with cyclonic activity in temperate regions or in tropical regions. It is caused due to the convergence of two different air masses with different temperatures.
• It is also known as frontal rain.
• Conventional rain is caused by convection currents.
• When the earth's surface is heated by conduction moisture-laden vapours rises because of heated air expands and becomes lighter this vapour condenses into cumulonimbus clouds. It is mostly associated with cumulonimbus clouds and thunderstorms.

The correct option is 3 i.e. A - 4, B - 2, C - 1, D - 3

• Jabalpur is famous for Automobile industry.
• Indian Army's Vehicle Factory division is at Jabalpur.
• Bengaluru is known as the Silicon Valley of India because it is well known for its IT industry.
• ​The Headquarters of ISRO and the Secretariat of the Department of Science is located in Bangalore.
• Mathura is well known for its petrochemical industries and oil refineries.
• ​Mathura Refinery of the Indian Oil Corporation is one of the biggest oil refineries of Asia.
• Ballarpur is located in Maharashtra is famous for the Paper industry.
• ​Ballarpur Industries Limited (BILT)  is located in Ballarpur is India's largest manufacturer of writing and printing paper.

The correct answer is The Western Yamuna Canal.

• The Western Yamuna canal is the most important in terms of area coverage in Haryana.

Key Points

• The Western Yamuna canal has most area coverage in Haryana and Delhi and it is a branch of the Yamuna river
• The Canal begins at the Hathnikund Barrage and has a total length of 3200 km.
• Its branches include the Sirsa branch, Hansi branch, Butana Branch, Sunder Branch, Jind branch, Munak Canal, Delhi Branch.
• Tributaries of Yamuna River:
• Left bank- Hindon, Tons, Giri, Rishiganga, Hanuman Ganga, Sasur Khaderi.
• Right bank- Chambal, Betwa, Ken, Sindh.

Additional Information

• The Bhakra Canal System provides an irrigation facility to 27.41 hectares of land in Haryana, Punjab, and Rajasthan.
• The BhakraSystem as a whole covers the area of District Kaithal,
  

Hisar, Sirsa, Fatehabad in Haryana, Ludhiana, Hashinagar, Ferozepur, and Jalandhar in Punjab and Bikaner in Rajasthan.

• ​Jawaharlal Nehru Canal is located in Haryana.
• It is situated east of Rasauli Distributary.
• Gurgan Canal is located in Haryana.
• It benefits Faridabad, Palwal, Mewat, and Gautam Buddha Nagar.
• has been drawn at the Okhla Barrage from the Yamuna.

The correct option is 4 i.e. Cell.

• Cells are the smallest unit of life showing the properties such as the capacity for metabolism, response to the environment, growth and reproduction.
• It is also called as 'building blocks of life'.
• It consists of a nucleus and cytoplasm and is contained within the cell membrane.
• Chromosomes are bundles of coiled DNA located within the nucleus of a cell.
• Various disorders are caused due to change in the number or structure of chromosomes.  
• | Syndrome | Abnormality | | --- | --- | | Down’s | Trisomy 21 | | Edwards’ | Trisomy 18 | | Patau’s | Trisomy 13 | | Turner | Monosomy X | | Klinefelter’s | XXY |

The correct option is 1 i.e. Oxygen

• Oxygen is released during the process of photosynthesis.
• Photosynthesis is the process involving the conversion of carbon dioxide gas, water, and minerals into sugar and oxygen.
• The release of oxygen is due to the process of photolysis of water.
• Manganese (Mn) is a metallic mineral nutrient present in leaves, which plays a key role in photosynthesis.
• Methane is called marsh gas and it is a powerful greenhouse gas
• It is also a principal component of natural gas.

CONCEPT:

Light-year:

• Light-year is a unit of length used to describe astronomical distances is light-year.
• The distance that light travels in a vacuum in one Julian year (365,25 days) is a light-year.

Amount of material:

• Mole is one of the units for measuring the unit of material
• 1 mole of any substance contains 6.022 × 10²³ atoms.

Amount of electrical charge:

• Coulomb is S.I unit for measuring the amount of charge

Energy:

• Power is defined as the rate of work done i.e.

$Power = \frac{{work;done}}{{time}}$

• Work = power × time
• As we know that Watt is the S.I unit of power.
• Work or energy = power × time = watt.hour

EXPLANATION:

Concept:

• Refraction is the change in the direction of propagation of light (electromagnetic wave) as it travels from one medium to another.
• This occurs due to a change in the velocity as well as the wavelength of light.
• As the wave moves from one medium to another, depending upon the particles, state and physical properties of the media, there is a change in the velocity and wavelength of the wave because of which it suffers deflection and change in direction.
• It can be expressed as

$\frac{{sini}}{{sinr}} = \frac{{{v_2}}}{{{v_1}}} = \frac{{{\lambda _2}}}{{{\lambda _1}}}$

Explanation:

When a light wave travels from rarer medium to denser medium, because of which its velocity decreases this can be seen as given below

$\frac{{sini}}{{sinr}} = \frac{{{v_2}}}{{{v_1}}}$

So as light travels from rarer to denser medium light will bend toward normal hence the angle of reflection (r) decreases and hence velocity in denser v₂ will decrease compared to v₁

Concept:

• If an object is placed between focal length and optical center the image will be formed on the same side behind the object and the image will be virtual and magnified

Explanation:

• If an object is placed between 2F and F real inverted and magnified
• If an object is placed at 2F image will be of the same size but inverted and real
• If an object is placed at F no image will be formed
• And if an object is placed between focal length and optical center the image will be formed on the same side behind the object and the image will be virtual and magnified

This can be seen as shown below