With reference to the distribution of isotherms in January, consider the following statements: 1. In the Northern Hemisphere, isotherms deviate to the north over the ocean. 2. In the Northern Hemisphere, isotherms deviate to the north over the continent. 3. The deviation of isotherms is more pronounced in the Northern Hemisphere than in the Southern Hemisphere. Which of the statements given above is/are correct?

Correct Option The correct option is 1 and 3 only. Explanation Isotherms are imaginary lines connecting places having equal temperatures. Their distribution is significantly influenced by the differential heating and cooling of land and water bodies. In January, it is winter in the Northern Hemisphere and summer in the Southern Hemisphere. The presence of vast landmasses in the Northern Hemisphere creates distinct temperature contrasts compared to the oceans. Statement-wise Analysis - Statement 1 is Correct: In January, the Northern Hemisphere experiences winter. During this season, the land surface cools more rapidly than the oceans. Consequently, the oceans are warmer than the continents at the same latitude. To connect points of equal temperature, an isotherm must shift poleward (to the north) over the warmer ocean to reach the latitude where the temperature drops sufficiently to match the land temperature. Thus, isotherms bend to the north over the Atlantic and Pacific oceans. - Statement 2 is Incorrect: Over the continents in the Northern Hemisphere during January, temperatures are significantly lower than over the adjacent oceans. To maintain the same temperature value, the isotherm must shift towards the equator (to the south) to find warmer conditions. Therefore, isotherms deviate to the south over the continents, not to the north. - Statement 3 is Correct: The Northern Hemisphere contains a much larger proportion of landmass compared to the Southern Hemisphere, which is predominantly covered by oceans. The strong contrast between land and water temperatures in the Northern Hemisphere causes isotherms to deviate significantly (zigzag pattern). In contrast, the Southern Hemisphere exhibits more regular isotherms that run largely parallel to the latitudes due to the uniform influence of the oceans. Key Takeaway Key Takeaway: During winter, isotherms bend poleward over warmer oceans and equatorward over colder continents. This deviation is far more pronounced in the Northern Hemisphere due to the extensive land-water contrast, whereas isotherms in the Southern Hemisphere are relatively straight.

NCERT Class 11 Geography — Chapter 2: Solar radiation, heat balance and temperature

mcqmedium

With reference to the distribution of isotherms in January, consider the following statements:

In the Northern Hemisphere, isotherms deviate to the north over the ocean.
In the Northern Hemisphere, isotherms deviate to the north over the continent.
The deviation of isotherms is more pronounced in the Northern Hemisphere than in the Southern Hemisphere.

Which of the statements given above is/are correct?

Official previous-year question

Verified 1 Aug 2026.

Options

A1 and 3 only
B1, 2 and 3
C2 only
D1 and 2 only

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Solution

Correct Option

The correct option is 1 and 3 only.

Explanation

Isotherms are imaginary lines connecting places having equal temperatures. Their distribution is significantly influenced by the differential heating and cooling of land and water bodies. In January, it is winter in the Northern Hemisphere and summer in the Southern Hemisphere. The presence of vast landmasses in the Northern Hemisphere creates distinct temperature contrasts compared to the oceans.

Statement-wise Analysis

Statement 1 is Correct: In January, the Northern Hemisphere experiences winter. During this season, the land surface cools more rapidly than the oceans. Consequently, the oceans are warmer than the continents at the same latitude. To connect points of equal temperature, an isotherm must shift poleward (to the north) over the warmer ocean to reach the latitude where the temperature drops sufficiently to match the land temperature. Thus, isotherms bend to the north over the Atlantic and Pacific oceans.
Statement 2 is Incorrect: Over the continents in the Northern Hemisphere during January, temperatures are significantly lower than over the adjacent oceans. To maintain the same temperature value, the isotherm must shift towards the equator (to the south) to find warmer conditions. Therefore, isotherms deviate to the south over the continents, not to the north.
Statement 3 is Correct: The Northern Hemisphere contains a much larger proportion of landmass compared to the Southern Hemisphere, which is predominantly covered by oceans. The strong contrast between land and water temperatures in the Northern Hemisphere causes isotherms to deviate significantly (zigzag pattern). In contrast, the Southern Hemisphere exhibits more regular isotherms that run largely parallel to the latitudes due to the uniform influence of the oceans.

Key Takeaway

Key Takeaway: During winter, isotherms bend poleward over warmer oceans and equatorward over colder continents. This deviation is far more pronounced in the Northern Hemisphere due to the extensive land-water contrast, whereas isotherms in the Southern Hemisphere are relatively straight.

Your note

More from Chapter 2: Solar radiation, heat balance and temperature

Which of the following best explains why the annual insolation received on 3rd January is slightly more than on 4th July?

easy

Consider the following data regarding the Heat Budget of the Earth: 1. 35 units are reflected back from the top of the clouds. 2. 14 units are absorbed within the atmosphere. 3. 51 units are absorbed by the earth’s surface. Which of the statements given above is/are correct?

hard

With reference to the heating of the atmosphere, consider the following statements: 1. Conduction is the process where heat is transferred through horizontal movement of air. 2. Convection is the process of vertical heating of the atmosphere. 3. Advection has no role in the diurnal variation of daily weather in middle latitudes. Which of the statements given above is/are correct?

medium

With reference to the variability of insolation at the surface of the Earth, consider the following statements: 1. The Earth receives slightly more annual insolation on 3rd January than on 4th July. 2. The variation in solar output due to the Earth's distance from the Sun has a drastic effect on daily weather changes. 3. The rotation of the Earth on its axis is one of the factors causing variations in insolation. Which of the statements given above is/are correct?

medium

Which of the following factors is/are responsible for the variations in insolation received at the surface of the Earth? 1. The angle of inclination of the sun’s rays 2. The transparency of the atmosphere 3. The configuration of land in terms of its aspect 4. The revolution of the Earth around the Sun has no influence on insolation variations Select the correct answer using the code given below:

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Correct Option

The correct option is 1 and 3 only.

Explanation

Statement-wise Analysis

Statement 1 is Correct: In January, the Northern Hemisphere experiences winter. During this season, the land surface cools more rapidly than the oceans. Consequently, the oceans are warmer than the continents at the same latitude. To connect points of equal temperature, an isotherm must shift poleward (to the north) over the warmer ocean to reach the latitude where the temperature drops sufficiently to match the land temperature. Thus, isotherms bend to the north over the Atlantic and Pacific oceans.
Statement 2 is Incorrect: Over the continents in the Northern Hemisphere during January, temperatures are significantly lower than over the adjacent oceans. To maintain the same temperature value, the isotherm must shift towards the equator (to the south) to find warmer conditions. Therefore, isotherms deviate to the south over the continents, not to the north.
Statement 3 is Correct: The Northern Hemisphere contains a much larger proportion of landmass compared to the Southern Hemisphere, which is predominantly covered by oceans. The strong contrast between land and water temperatures in the Northern Hemisphere causes isotherms to deviate significantly (zigzag pattern). In contrast, the Southern Hemisphere exhibits more regular isotherms that run largely parallel to the latitudes due to the uniform influence of the oceans.