Previous Year UPSC Questions

Explanation

Option (c) is correct: Khasi belongs to the Austroasiatic (Austric) language family, specifically the Mon-Khmer branch, and is spoken mainly in Meghalaya, India.

Option (a) is incorrect: Marathi is an Indo-Aryan language spoken in Maharashtra.

Option (b) is incorrect: Ladakhi is a Tibeto-Burman language spoken in Ladakh.

Option (d) is incorrect: Tamil is a Dravidian language spoken in Tamil Nadu.

Explanation

Option (c) is correct: A Price Index measures the average change in prices of a selected basket of goods and services over time, relative to a base year. In this context, with 1960 as the base year (index value set at 100), a current price index of 330 indicates that the weighted average price of the selected items has increased by 3.3 times since 1960.

Option (a), (b) and (d) are incorrect:

A price index is based on a specific basket of goods and services and not all items in the economy. Therefore, it does not imply that all items have increased in price by 3.3 times. The price index reflects the weighted average change in prices of the entire basket and not individual selected items. The price index pertains to a broad basket of goods and services and does not provide information about specific commodities like gold.

Explanation

The Eco Mark is a certification issued by the Bureau of Indian Standards (BIS) for products that meet environmental sustainability criteria. It is awarded to goods that have minimal adverse effects on the environment throughout their lifecycle, including production, use, and disposal. The mark helps consumers identify eco-friendly products and promotes sustainable manufacturing practices.

Explanation

Assertion A is true: Phenyl, a common household germicide, contains phenol derivatives that disrupt bacterial cell membranes and denature proteins, making it effective against germs. Reason R is true: Phenol, also called carbolic acid, is a well-known antiseptic and disinfectant due to its ability to kill bacteria, fungi, and viruses. This explains the germicidal property of phenyl. Thus, both Assertion (A) and Reason (R) are true, and R correctly explains A.

Explanation

Water pollution in rivers is primarily measured by the Dissolved Oxygen (DO) level, which indicates the amount of oxygen available for aquatic organisms. A low DO level signifies high pollution, as pollutants like organic waste decompose and consume oxygen, making the water uninhabitable for aquatic life. BOD (Biochemical Oxygen Demand) is the amount of oxygen required by microorganisms to decompose organic matter in water over a specific period (usually 5 days at 20°C). High BOD indicates organic pollution, such as from sewage or agricultural runoff, while low BOD signifies cleaner water. COD (Chemical Oxygen Demand) is the total amount of oxygen required to chemically oxidize both organic and inorganic matter in water. COD provides a broader measure of pollution than BOD, including oxygen demand from inorganic substances.

Explanation

A consumer is said to be in equilibrium when they allocate their limited income in such a way that they maximize their total satisfaction (utility) from the goods and services they consume i.e. he is able to fulfil his need with a given level of income. This concept is based on the theory of consumer behavior in economics. Conditions for Consumer Equilibrium:

Budget Constraint: The consumer has a fixed level of income and faces given prices for goods and services. The total expenditure on goods and services cannot exceed the consumer’s income. Utility Maximization: The consumer allocates their income in such a way that the marginal utility per unit of money spent is equal across all goods and services. No Further Reallocation: The consumer cannot increase their total utility by reallocating their income between goods and services.

Explanation

Supply-side economics is an economic theory that focuses on boosting economic growth by increasing the supply of goods and services. It emphasizes the role of producers (businesses and entrepreneurs) in driving economic activity. The key principles of supply-side economics include:

Tax Cuts: Reducing taxes on businesses and individuals to incentivize production, investment, and work. Deregulation: Reducing government regulations to lower the cost of production and encourage entrepreneurship. Incentives for Investment: Providing incentives for businesses to invest in capital, technology, and innovation. Increased Productivity: Focusing on policies that enhance productivity and efficiency in the economy. Supply-side economics emphasizes the producer’s perspective because it believes that by enabling producers to operate more efficiently and profitably, the overall economy will grow. This growth, in turn, benefits consumers through increased employment, lower prices, and higher quality goods and services.

Explanation

Ergotism is historically known as "St. Anthony’s Fire" is directly linked to the consumption of grains (such as rye, barley, wheat, and oats) contaminated with the ergot fungus (Claviceps purpurea). The fungus infects the grains, producing sclerotia (ergot bodies) that contain toxic alkaloids. These alkaloids can cause two forms of ergotism:

Convulsive ergotism which is cracterized by seizures, hallucinations, and muscle spasms. Gangrenous ergotism which leads to restricted blood flow, causing tissue death and gangrene in extremities.

Explanation

In industrial applications, a wide range of microorganisms are used due to their ability to carry out various biochemical processes that are beneficial for different industries. The following microorganisms are widely used:

Bacteria is used in industries such as fermentation, bioremediation, and food production (e.g., yogurt, cheese, and antibiotics). Microalgae is used in the production of biofuels, aquaculture feed, and nutraceuticals. They are also involved in carbon sequestration. Fungi is widely used in the pharmaceutical industry for the production of antibiotics (such as penicillin) and enzymes. They are also used in fermentation and the production of organic acids.

Explanation

A is matched with 4: Fruit develops from the ovary of the flower after fertilization. The ovary, which contains the ovules, transforms into the fruit as the seeds inside mature. This process is an essential part of the plant’s reproductive cycle. B is matched with 1: Seed originates from the ovule after fertilization. The ovule, located inside the ovary, contains the female gamete (egg cell). Once fertilized by the male gamete (pollen), the ovule develops into a seed, which contains the embryo and stored food for the new plant. C is matched with 3: Wood is produced from the stem of the plant. The stem, with its vascular tissues (xylem and phloem), supports the plant and transports nutrients. The xylem, which is a type of vascular tissue, forms the wood, providing structural support and helping in water transport. D is matched with 2: Starch is primarily produced in the leaf. During photosynthesis leaves use sunlight, water, and carbon dioxide to produce glucose. Some of this glucose is converted into starch, a storage form of sugar, and is stored in the chloroplasts of the leaf.