Question

Consider a specific point on the earth (say, the city of Delhi). The temperature at a given time of the day (say, 12.00 noon) will in general be higher in summer than in winter because ____________________.

• A. the earth is closer to the sun in summer than in winter
• B. sun-rays falling on the earth are inclined (slanting) more towards the surface of the earth in winter
• C. evaporation of water from atmospheric-precipitaion occurring in winter alone
• D. the axis of the earth is inclined more towards the sun in winter

Answer 1

Answer: (B)

sun-rays falling on the earth are inclined (slanting) more towards the surface of the earth in winter

• The principle factor deciding the temperature of any place on Earth is the angle of sun rays falling upon the surface of the earth. Vertical rays i.e. rays inclined towards the surface bring in more insolation thus earth gets warmer. On the other hand, when the sun rays are inclined away from the earth's surface i.e. slanting rays, brings in less insolation and thus temperature remains cooler. Thus B is correct.
• Option A is wrong as the distance from the sun does not contribute significantly towards the variation in temperature on earth.
• Option C is wrong as evaporation occurs in all the seasons.
• Option D is wrongly stated.