The Insolation

Total Questions: 10

1. Consider the following statements and answer the question with the help of codes given below: [U.P.P.C.S. (Pre) 1997]

Assertion (A) : The atmosphere receives most of the heat only indirectly from the sun and directly from the earth's surface.

Reason (R) : The conversion from shortwave solar to long wave terrestrial energy takes place at the earth's surface.

Code:

(a) Both (A) and (R) are true, and (R) is the correct explanation of (A)
(b) Both (A) and (R) are true, but (R) is not the correct explanation of (A).
(c) (A) is true, but (R) is false.
(d) (A) is false, but (R) is true.

Correct Answer: (a) Both (A) and (R) are true, and (R) is the correct explanation of (A)

Solution:The principal source of atmospheric and Earth's surface energy is the Sun. Insolation is the incoming solar Energy intercepted by the Earth. The energy radiated from the Sun is known as short-wave solar radiation whereas the energy radiated from Earth is known as long-wave radiation. The long-wave radiation is absorbed by the atmospheric gases particularly by carbon dioxide and the other green- house gases. Thus, the atmosphere is indirectly heated by the Earth's radiation. Increasing concentration of greenhouse gases such as carbon dioxide and methane increases the temperature of the lower atmosphere by restricting the outward passage of emitted radiation, resulting in global warming.

2. Normally, the temperature decreases with the increase in height from the Earth's surface, because [I.A.S. (Pre) 2012]

1. The atmosphere can be heated upwards only from the Earth's surface.

2. There is more moisture in the upper atmosphere.

3. The air is less dense in the upper atmosphere.

Select the correct answer using the codes given below :

(a) Only 1
(b) 2 and 3
(c) 1 and 3
(d) 1, 2 and 3

Correct Answer: (c) 1 and 3

Solution:Globally, insolation is the main factor behind the distribution of temperature. By absorbing Sunrays, the surface of Earth gets warmer. This is the reason why temperature decreases as height increases. At high altitude air density is less with little humidity. Hence, statement (1) and (3) are correct while (2) is wrong. Therefor, option (c) is the correct answer.

3. Which one of the following reflects more sunlight as compared to the three? [I.A.S. (Pre) 2010]

(a) Sand desert
(b) Paddy cropland
(c) Land covered with fresh snow
(d) Prairie land

Correct Answer: (c) Land covered with fresh snow

Solution:Albedo is the fraction of solar energy (short wave radiation) reflected from the Earth back into space. It is a measure of the reflectivity of the Earth's surface. Land covered with fresh snow has a high albedo (75-95%), most sunlight hitting the surface bounces back towards space. The average albedo of Earth is 30%. The sand desert has albedo 20-30%. Paddy cropland has albedo 3-15% and Prairie land has albedo 10-20%.

4. Read the following statements and choose the correct option: [Chhattisgarh P.C.S. (Pre), 2022]

1. Moving away from the sea-force of tropical cyclones decreases.

2. Tropical cyclone gets its energy from release of latent heat on account of condensation of moisture that wind gathers after moving over the occean which decreases as it moves away from sea.

(a) 1 and 2 both are true, and 2 is correct reasonig of 1.
(b) 1 and 2 both are true, but 2 is not correct reasoning of 1.
(c) 1 is true, but 2 is false.
(d) 1 and 2 both are false.

Correct Answer: (a) 1 and 2 both are true, and 2 is correct reasonig of 1.

Solution:Moving away from the sea, force of tropical cyclone de- creases become tropical cyclones get their energy from relesase of latent heat on account of condensation of moisture that wind gathers after moving over the ocean which de- creases as it moves away from sea.

5. Which one of the following is associated with 'Albedo'? [U.P. P.C.S. (Pre) 2019]

(a) Transmitting power
(b) Absorbing power
(c) Emissive power
(d) Reflecting power

Correct Answer: (d) Reflecting power

Solution:Albedo is the fraction of light that a surface reflets. Significantly frozen ice will have a high albedo, which means it reflects solar radition into space, while green areas such as forests and plains will have a low albedo.

6. Consider the following statements: [I.A.S. (Pre) 2007]

1. The annual range of temperature is greater in the Pacific Ocean than that in the Atlantic Ocean.

2. The annual range of temperature is greater in the Northern Hemisphere than that in the Southern Hemisphere.

Which of the statements given above is/are correct?

(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

Correct Answer: (b) 2 only

Solution:More the size of the ocean, less the variation in the annual temperature. Therefore, more temperature variation is found at the Atlantic Ocean as compared to the Pacific Ocean.

7. Which of the following statements is not true: [U.P.P.C.S. (Pre) 2002]

(a) Presence of water vapour is highly variable in the lower atmosphered
(b) The zone of maximum temperature is located along the equator
(c) Frigid zones are located in both the hemispheres between the polar circles and the poles.
(d) Jet streams are high altitude winds affecting the surface weather conditions.

Correct Answer: (b) The zone of maximum temperature is located along the equator

Solution:The average, temperature decreases from the Equator towards the higher degree latitude. It may be noted that the highest temperature is never recorded at the Equator, instead, it is recorded at the 20°N. So, it can be said that the zone of maximum temperature is not located at the equator. Therefore, staement (b) is not correct, other statements are correct.

8. The highest temperature on the earth is recorded at - [M.P.P.C.S. (Pre) 2010]

(a) Equator
(b) 10° North Latitude
(c) 20° North Latitude
(d) 25° North Latitude

Correct Answer: (c) 20° North Latitude

9. Clear sky nights are cooler than cloudy sky nights due to [39th B.P.S.C. (Pre) 1994]

(a) condensation
(b) radiation
(c) induction
(d) conduction

Correct Answer: (b) radiation

Solution:

The cloudy night contains more water vapour than a clear night. The heat emitted from the Earth's surface is trapped by the clouds and emitted back towards the earth. As a result cloudy night seems warmer than clear night. If the sky is clear, heat emitted from the Earth's surface freely escapes into space, resulting in colder temperatures.

10. With reference to the Earth's atmosphere, which one of the following statements is correct? [I.A.S. (Pre) 2023]

(a) The total amount of insolation received at the equator is roughly about 10 times of that received at the poles.
(b) Infrared rays constitute roughly two-thirds of insolation.
(c) Infrared waves are largely absorbed by water vapour that is concentrated in the lower atmosphere.
(d) Infrared waves are a part of visible spectrum of electromagnetic waves of solar radiation.

Correct Answer: (c) Infrared waves are largely absorbed by water vapour that is concentrated in the lower atmosphere.

Solution:The largest amount of energy that reaches the earth's surface is in short wavelengths. The energy that the earth receives is referred to as insolation, or incoming solar radiation. Notably, shortwave solar energy can pass through the atmosphere quite easily. Before reaching the surface of the earth, the incoming solar energy travels through the atmosphere. A large portion of the near-infrared light is absorbed by water vapor, ozone, and other gases in the troposphere.

Due to this reason assertion (c) is true.