Previous Year UPSC Questions

Explanation

Somprakash was started by Ishwar Chandra Vidyasagar and played a pivotal role in fostering nationalism during the era of colonial India. Its weekly publication every Monday earned it the name "Somprakash." Its impact was particularly pronounced in raising the awareness of the ryots, challenging landlord injustices and the exploitation of indigo farmers and vociferously criticizing the British taxation policies that burdened the impoverished masses. Moreover, it played a significant role in advocating for industrialization.

Explanation

Chandra Vidyasagar (1820-1891) was a renowned Bengali social reformer, educator, and writer during the 19th century. He played a pivotal role in advocating for women’s rights, including widow remarriage and the abolition of polygamy. The book "Bahubivah" (Polygamy) was written by Vidyasagar as a critique of the practice of polygamy in Hindu society. He argued against the custom, highlighting its detrimental effects on women and families. His work was part of a broader effort to reform Hindu social practices and promote gender equality. His writings and activism contributed significantly to the passage of the Widow Remarriage Act of 1856 and other social reforms in colonial India.

Explanation

Option (a) is correct: Computed Tomography (CT), also known as a CT scan, uses X-rays to create detailed cross-sectional images of the internal structures of the human body. The X-rays rotate around the body, and a computer processes the data to generate 3D or 2D images. Options (b), (c) and (d) are incorrect:

Sound waves are used in ultrasound imaging not in CT Scans. Magnetic resonance is associated with MRI, which uses magnetic fields and radio waves, not X-rays. Radio isotopes are used in nuclear medicine, such as PET scans.

Explanation

Option (d) is correct: Crookes glass is a type of glass that can absorb and block ultraviolet (UV) rays. It is specially designed to cut off UV radiation while allowing visible light to pass through. This makes it useful in applications where protection from UV light is needed, such as in certain laboratory equipment or sun protection glasses. Options (a), (b) and (c) are incorrect: Soda glass is a common type of glass used for general purposes, but it does not have UV-blocking properties. Pyrex glass is known for its heat resistance and is used in laboratory equipment but does not specifically block UV rays. Jena glass is a type of glass with special properties, mainly used in scientific instruments, but it is not specifically designed to block ultraviolet rays.

Explanation

The Government of India launched the National Child Labour Project (NCLP) in 1988 to rehabilitate children employed in hazardous industries and occupations. This central sector scheme involved identifying child laborers, removing them from hazardous work, enrolling them in Special Training Centres (STCs), providing necessary training, and mainstreaming them into formal education.

Statement 1 is incorrect: It is run by the Ministry of Labour and Employment.

Statement 2 is correct: The Gurupadaswamy Committee was formed by the Government of India in 1979 to study child labor and suggest ways to address it.

Explanation

Participatory Notes (PNs) are financial instruments used by Foreign Institutional Investors (FIIs) to invest in Indian stock markets without direct registration with the Securities and Exchange Board of India (SEBI). These instruments allow overseas investors, including hedge funds, to gain exposure to Indian equities while bypassing regulatory procedures. PNs are issued by registered FIIs and sub-accounts against underlying Indian securities. While they provide easy access to foreign investment, concerns exist regarding lack of transparency and potential misuse for money laundering.As per SEBI regulations, efforts have been made to increase transparency and reduce misuse of PNs in India’s financial markets.

Explanation

Selenium is a semiconductor, meaning it has electrical conductivity that lies between that of metals and insulators. Its conductivity increases with exposure to light, making it useful in solar cells and photoelectric applications. Therefore, selenium is not a poor conductor of electricity.

Explanation

Option (c) is correct: Zinc oxide (ZnO) is commonly referred to as philosopher’s wool. It is known as philosopher wool due to its wool-like texture. This name comes from the historical belief that zinc oxide could be produced by heating zinc metal in air, and it was once used by alchemists in their experiments. Zinc oxide is a white powder with applications in Cosmetics (UV-blocking in sunscreens), Rubber (activator in vulcanization), Paints (pigment, mildew-resistant) and Pharmaceuticals (antiseptic in ointments). Options (a), (b) and (d) are incorrect:

Zinc bromide (ZnBr₂) is used in dry cell batteries and photography. Zinc nitrate (Zn(NO₃)₂) is used in fertilizers and as a laboratory reagent. Zinc chloride (ZnCl₂) is used in chemical production and water treatment. None of these compounds are associated with the term "philosopher’s wool," which refers to zinc oxide (ZnO).

Explanation

Option (b) is correct: German silver does not contain any silver at all. Alloy of copper (60%), nickel (20%), and zinc (20%). No actual silver content. Known for hardness, corrosion resistance, and silver-like appearance. Commonly used in jewelry, musical instruments, and coins. Options (a), (c) and (d) are incorrect:

Horn silver (also known as silver chloride, AgCl), gray, heavy halide mineral. Found in oxidized zones of silver-bearing veins. It is associated with silver and silver related minerals. Ruby silver: Collective term for pyrargyrite and proustite, both silver-bearing minerals with striking red colors. While Pyrargyrite(deep red color) is silver antimony sulfide (Ag₃ SbS₃) and Proustite (Scarlet red color) is Silver arsenic sulfide (Ag₃ AsS₃). Both crystallize in the trigonal system and possess a Mohr’s hardness of 2.5 and specific gravity of 5.82.. Lunar caustic: Another name for silver nitrate (AgNO₃). An inorganic compound containing silver. Has antiseptic properties. Used in various medical applications, including the treatment of warts and as a cauterizing agent.

Explanation

Option (d) is correct: Cyclonite is another name for RDX (Research Department Explosive or Royal Demolition Explosive), which is a powerful military-grade explosive. It is widely used in military applications and mining operations due to its high detonation velocity and stability. Options (a), (b) and (c) are incorrect:

Cyanohydrin is a type of organic compound used in the synthesis of plastics and pharmaceuticals, not an explosive. Dextran is a complex sugar used in medical applications like blood volume expanders. Cyclohexane is a hydrocarbon commonly used as a solvent or in chemical synthesis, not an explosive.