Search Previous Year Questions

The correct answer is A lichen.

Key Points

• Litmus, a natural pH indicator, is derived from lichens, which are symbiotic organisms formed by the association of fungi and algae.
• Lichens are mainly found in cold and temperate regions, growing on rocks, trees, and soil. They are known for their ability to survive in extreme environmental conditions.
• Litmus is produced by processing specific species of lichen, such as Roccella tinctoria, which are rich in coloring substances.
• The litmus solution is used to detect the pH level of substances, turning red in acidic conditions and blue in alkaline conditions.
• Lichens have historically been used not only for litmus production but also as a source of dyes and medicines due to their unique chemical properties.

Additional Information

• Lichens:
• Definition: Lichens are composite organisms formed through a symbiotic relationship between fungi and algae or cyanobacteria.
• Characteristics: They are capable of surviving in extreme conditions and play an important role in ecosystems by contributing to soil formation and nutrient cycling.
• Uses: Apart from producing litmus, lichens are used as natural dyes, in perfumes, and as medicines to treat wounds and infections.
• Examples: Common lichen species used for litmus production include Roccella tinctoria and Lecanora.
• pH Indicators:
• Litmus: A natural indicator derived from lichens, used to test acidity or alkalinity.
• Other natural indicators: Turmeric, red cabbage extract, and beetroot juice are also used as natural pH indicators.
• Synthetic indicators: Phenolphthalein and methyl orange are examples of synthetic indicators used in laboratories.
• Comparison with other options:
• Red algae: While red algae like Gelidium and Gracilaria are used for producing agar, they are not a source of litmus.
• Fungi: Fungi contribute to the symbiotic relationship in lichens but do not directly produce litmus.
• Brown algae: Brown algae, such as Sargassum, are primarily used in food and industrial applications, not for litmus production.
• Significance of Litmus:
• Litmus is widely used in laboratories and industries for quick and simple pH testing.
• It plays a crucial role in applications like water testing, food quality control, and chemical manufacturing.

The correct answer is Option 2: i - 2, ii - 1, iii - 5, iv - 4, v - 3.

Key Points

• Sublimation: It refers to the direct transformation of a substance from the solid phase to the gas phase without passing through the liquid phase. This process is typically observed in substances like dry ice (solid carbon dioxide). Hence, statement i matches with 2.
• Distillation: It is a method of separation that relies on differences in the boiling points of components in a mixture. This process is commonly used for purifying liquids. Hence, statement ii matches with 1.
• Evaporation: This process involves the change of a liquid into a vapor at a temperature below its boiling point. It is often used for separating a liquid from dissolved solids. Hence, statement iii matches with 5.
• Filtration: This is a physical method used to separate a solid from a liquid by passing the mixture through a filter medium. It is widely used in laboratories and industries. Hence, statement iv matches with 4.
• Condensation: This refers to the transformation of a gas into a liquid, typically due to cooling. For instance, water vapor in the air condenses into liquid water when cooled. Hence, statement v matches with 3.

Additional Information

• Sublimation:
• Sublimation is commonly observed in substances like iodine, naphthalene, and dry ice.
• It is a useful process in industries for purifying compounds and in creating products like freeze-dried foods.
• It occurs under specific conditions of temperature and pressure, often at reduced pressure.
• Distillation:
• It is categorized into various types, such as simple distillation, fractional distillation, and steam distillation, depending on the application.
• Fractional distillation is commonly used in oil refineries to separate crude oil into various fractions like diesel, kerosene, and petrol.
• Distillation is also used in alcoholic beverage production to concentrate ethanol.
• Evaporation:
• Evaporation plays a significant role in natural processes like the water cycle, where water from oceans and rivers evaporates and forms clouds.
• It is also used in industrial applications such as salt production from seawater.
• Factors like temperature, surface area, and airflow affect the rate of evaporation.
• Filtration:
• Filtration is widely used in water purification systems to remove impurities and sediments.
• It is also employed in various industries, such as pharmaceuticals, food processing, and chemical manufacturing.
• Filters can range from simple paper filters to advanced membrane filters used for microfiltration and ultrafiltration.
• Condensation:
• Condensation is essential in refrigeration and air conditioning systems, where gases are cooled and condensed into liquids.
• It is a key process in the water cycle, leading to the formation of dew, fog, and clouds.
• Condensation occurs when a gas loses thermal energy and its molecules come closer together.

Important Points

• Sublimation: Sublimation is utilized in freeze-drying techniques, which are employed in food preservation and pharmaceutical industries.
• Distillation: Distillation is critical in chemical laboratories for purifying solvents and isolating chemical compounds.
• Evaporation: Evaporation is influenced by environmental factors such as humidity, wind speed, and ambient temperature.
• Filtration: Filtration systems are pivotal in ensuring clean drinking water and maintaining hygiene in medical environments.
• Condensation: Condensation forms the basis of cloud formation and precipitation, which are vital for sustaining ecosystems.

The correct answer is option 4.

Key Points

• Simlipal Biosphere Reserve – Located in Odisha, it is known for its tiger reserve and rich biodiversity.
• Nokrek Biosphere Reserve – Situated in Meghalaya, it is famous for its rare citrus species and is a UNESCO-recognized biosphere reserve.
• Agasthyamalai Biosphere Reserve – Spread across Kerala and Tamil Nadu, it is part of the Western Ghats and harbors unique flora and fauna.
• Manas Biosphere Reserve – Found in Assam, it is a UNESCO World Heritage Site and known for its rich biodiversity, including the golden langur and pygmy hog.

Given:   

Profit% = 54%

Discount% = 1%                          

Formula Used:

Profit = SP – CP

Discount = MP – SP

Profit% = (Profit /CP) × 100 

Discount% = (Discount /MP) × 100

SP = {(100 + P%)/100} × CP

SP = {(100 – D%)/100} × MP

Where P is Profit, D is discount, CP is cost price, SP is selling price and MP is maximum retail price.

Calculation:

SP = {(100 + P%)/100} × CP

SP = {(100 – D%)/100} × MP

⇒ {(100 + P%)/100} × CP = {(100 – D%)/100} × MP

⇒ (100 + P%) × CP = (100 – D%) × MP 

⇒ CP/MP = (100 – D%)/(100 + P%)

⇒ Putting D = 1 and P = 54

⇒ CP/MP = 99/154

⇒ 9/14

⇒ CP ∶ MP = 9 ∶ 14

⇒ SP = (154/100) × CP

⇒ SP = (77/50) × CP

⇒ SP/CP = 77/50

⇒ CP ∶ SP = 50 ∶ 77

⇒ Only I is incorrect.

∴ II and III are correct.

The correct answer is Kulasekarapattinam, Tamil Nadu.

In News

• ISRO’s Kulasekarapattinam spaceport in Tamil Nadu will launch its first Small Satellite Launch Vehicle (SSLV) in 2027.

Key Points

• Kulasekarapattinam spaceport is ISRO’s second launch complex outside Andhra Pradesh.
• SSLV from this spaceport will support polar satellite launches of up to 500 kg, enhancing India's small satellite launch capabilities.
• The spaceport will be fully commissioned in 24 months, with Indian industry participation in SSLV production.
• ISRO Chairman V. Narayanan confirmed the launch timeline at IIT Madras, inaugurating the S. Ramakrishnan Centre of Excellence for Research.

Additional Information

• Sriharikota, Andhra Pradesh
• Home to ISRO’s primary launch facility, the Satish Dhawan Space Centre (SDSC).
• Chandipur, Odisha
• Used for launching missile systems under the DRDO’s Integrated Test Range (ITR).
• Mahendragiri, Tamil Nadu
• ISRO’s propulsion testing center, used for testing cryogenic and liquid propulsion engines.

Answer: C

Key Points

• The Moist deciduous forests are found in the regions which record rainfall b/w 100-200 cm.
• These forests are found in the NE states along the foothills of Himalayas, eastern slopes of the Western Ghats & Odisha.
• Teak, sal, shisham, hurra, mahua, amla, semul, kusum, and sandalwood etc. are the main species of these forests.

The correct answer is 500 GW.

Key Points

• India has set an ambitious target of achieving 500 GW of renewable energy installed capacity by the year 2030.
• This target includes contributions from various renewable sources such as solar, wind, hydropower, and biomass.
• The initiative is part of India's commitment under the Paris Agreement to combat climate change and reduce carbon emissions.
• India aims to fulfill 50% of its energy requirements from renewable sources by 2030.
• As of 2023, India has already achieved around 125 GW of renewable energy capacity, showcasing significant progress toward the 2030 goal.

Additional Information

• National Solar Mission (NSM):
• Launched in 2010, NSM is part of India's National Action Plan on Climate Change (NAPCC).
• It aims to establish India as a global leader in solar energy by achieving a target of 100 GW of solar capacity by 2022.
• Paris Agreement:
• An international treaty adopted in 2015 to combat climate change.
• India pledged to reduce its carbon intensity by 33-35% by 2030 compared to 2005 levels.
• Renewable energy targets are a key component of India's commitment under this agreement.
• International Solar Alliance (ISA):
• Founded by India and France in 2015, ISA is a treaty-based intergovernmental organization.
• Its objective is to promote the use of solar energy globally and mobilize financial resources for its expansion.
• Green Energy Corridor Project:
• A government initiative to integrate renewable energy into India's power grid.
• The project involves setting up transmission networks to handle renewable energy efficiently.

Answer: B

 

Key Points

 

• The UTs were introduced in the States Reorganization Act 1956 by 7^th Constitutional amendment Act 1956. Hence, statement 1 is correct
• 42^nd Constitutional amendment Act,1976 made the president bound to the advice of the cabinet. Hence, statement 2 is wrong.
• 97^th Constitutional Amendment Act gave constitutional status to the Cooperative societies by inserting part IX-B to the Constitution of the country. Hence, statement 3 is correct.
• The term Socialist , Secular & Integrity in constitution is added by 42^nd Amendment Act. Hence, statement 4 is correct.

The correct answer is option 3.

Key Points

• Sita Kund – Located ~6 km east of Munger town. It's a well-known hot spring in Munger district tied to Ramayana lore
• Rishi Kund – Situated ~9 km south of Sita Kund, nestled in Munger’s Kharagpur hills
• Gaumukh Kund – Also listed among the principal hot springs in the Munger area
• Nanak Kund – This spring is linked to Rajgir in Nalanda district, not Munger

Additional Information

List of Hot Springs in Bihar:

The correct answer is (2v₁v₂)/(v₁ + v₂)

Solution:

Let the total distance = 2d

First half distance = d

Second half distance = d

Time taken for first half

t₁ = d/v₁

Time taken for second half

t₂ = d/v₂

Total distance

= 2d

Total time

= d/v₁ + d/v₂

Average speed

= Total Distance / Total Time

= 2d / (d/v₁ + d/v₂)

= 2d / [d(v₁ + v₂)/(v₁v₂)]

= 2v₁v₂ / (v₁ + v₂)

Hence, the average speed is

(2v₁v₂)/(v₁ + v₂)