UPSC CSE 1980

During a solar eclipse, the Moon casts a shadow on Earth, blocking the sunlight partially or completely.
Explanation:


Why other options are incorrect:
(a) Earth comes between sun and moon: This would be a lunar eclipse, where the Earth’s shadow falls on the Moon.
(b) Moon is at right angle to the earth: The orientation of the Moon relative to the Earth is not the defining factor for a solar eclipse. It’s the relative positions of the Moon, Earth, and Sun.
(d) Sun comes between moon and earth: This is physically impossible, as the Moon is much smaller than the Sun and cannot come between it and Earth.

The weight of an object at the poles is greater than at the equator as (d) Gravitational pull is more at the poles.
Explanation: The Earth is not a perfect sphere; it’s slightly flattened at the poles and bulges at the equator. Because of this shape, the distance from the center of the Earth to the surface is shorter at the poles than at the equator. Since gravity is inversely proportional to the distance from the center of the Earth, the gravitational pull is stronger at the poles where the distance is shorter.


Why other options are incorrect:
(a) Of the shape of the earth: While the shape of the Earth is the key reason for the difference in gravity, option D more directly states the reason, which is the resulting difference in gravitational pull.
(b) The attraction of the moon is maximum at the earth’s surface: The moon’s gravitational influence is primarily responsible for tides, not the difference in weight between the poles and equator.
(c) The attraction of the sun is maximum at the earth’s surface: The sun’s gravitational influence is much weaker than the Earth’s and is relatively constant across the planet.

The correct answer is (b) Koyna.
Explanation: Koyna Hydroelectric Project: Considered the largest completed hydroelectric power plant in India, with a capacity of 1960 MW.
Why Other Options are incorrect
(a) Bhakra Nangal Project: While a significant hydroelectric project, it is not as large as Koyna. It has a capacity of 1,325 MW.
(c) Hirakud Project: Another large hydroelectric project in India, but not as large as Koyna. The Hirakud Dam has an installed capacity of 359.8 MW
(d) Salal Project: Another large hydroelectric project in India, but not as large as Koyna. The Salal Project, has a total installed capacity of 690 MW

The correct answer is (d) It caters mostly to the rural population.
Explanation: Cottage industries are characterized by small-scale production often done at home or in small workshops using readily available local raw materials and simple tools. They typically employ a large number of people from the local community, often working with family members. While some products might not require power for production, the main reason for high production despite low productivity is their focus on catering to the local rural population where demand for their goods is high and the infrastructure for large-scale production is limited.
Why other options are incorrect:
(a) It employs a large number of people: While cottage industries do employ a large number of people, this is not the primary reason for their high production. The high number of employees is a consequence of the labor-intensive nature of cottage production, not the cause of its high output.
(b) No power is needed to manufacture most of the products: While some cottage industries may not require significant power usage due to their simple technology, this is not the main reason for their high production. Many cottage industries do utilize power, especially in more modern setups.
(c) Raw material is generally available locally: Although readily available local raw materials is a characteristic of cottage industries, it’s not the direct cause of high production. Local raw materials contribute to lower costs and accessibility, but the high production volume stems from the ability to cater to the large local rural demand with a simple production setup.

The principal language of Nagaland is (a) English.
Explanation: Nagaland’s official language is English, used in government, education, and other official contexts.
Why other options are incorrect
(b) Naga: While various Naga languages are spoken by different tribes, they are not the official or principal language of the state.
(c) Assamese: Assamese is a major language in neighboring Assam, but is not the official language of Nagaland.
(d) Khasi: Khasi is the language spoken in the state of Meghalaya, not Nagaland.

The correct answer is (c) In cloudy nights the radiation takes place very slowly.
Explanation: Dew forms when the ground cools down enough at night, causing moisture in the air to condense. However, on cloudy nights, clouds trap the Earth’s radiated heat, preventing the ground from cooling sufficiently to produce dew. This slow radiation process due to the presence of clouds is why less dew is formed on cloudy nights.


Why other options are incorrect:
(a) Clouds absorb the falling dew: While clouds can absorb moisture, they don’t actively absorb falling dew. Dew forms on the ground before it potentially reaches the clouds.
(b) Clouds scatter moisture: Clouds do scatter some moisture, but this scattering doesn’t prevent dew formation. It’s the absorption of Earth’s radiation by clouds that hinders dew formation.
(d) In cloudy nights the radiation takes place very quickly: This option is the opposite of the correct answer. On cloudy nights, radiation is significantly slowed down due to the clouds’ ability to trap heat.

Correct answer is C

Correct answer is C

Correct answer is C

Correct answer is C

Correct answer is C

Correct answer is C

Correct answer is C

Correct answer is C

Correct answer is C

Correct answer is C

Correct answer is C

Correct answer is C

Correct answer is C

Correct answer is C

Correct answer is C

Correct answer is C

Correct answer is C

Correct answer is C

Correct answer is C

Correct answer is C

Correct answer is C

Correct answer is C

Correct answer is C