Q1. Less dew is formed on cloudy nights because
(a) Clouds absorb the falling dew
(b) Clouds scatter moisture
(c) In cloudy nights the radiation takes place very slowly
(d) In cloudy nights the radiation takes place very quickly
(UPSC Prelims 1979)
Answer: (c) In cloudy nights the radiation takes place very slowly
Explanation: On cloudy nights, infrared radiation from the Earth’s surface is trapped by clouds, preventing rapid cooling. Since dew formation requires surface cooling, the slow radiation loss reduces the likelihood of dew.
Q2. Isohyets are the lines drawn on a map connecting points having
(a) Equal temperature
(b) Equal height
(c) Equal atmospheric pressure
(d) Equal rainfall
(UPSC Prelims 1985)
Answer: (d) Equal rainfall
Explanation: Isohyets are lines on a map that connect points of equal rainfall. They are used in meteorology and climatology to study precipitation patterns across regions.
Q3. The areas in India that receive approximately an average of more than 200 cm of rainfall annually are
(a) Meghalaya, Assam, Nagaland, Arunachal Pradesh
(b) Orissa, Madhya Pradesh, Gujarat, Maharashtra
(c) Meghalaya, Assam, Rajasthan, Jammu & Kashmir
(d) Meghalaya, Delhi, Punjab, Rajasthan
(UPSC Prelims 1986)
Answer: (a) Meghalaya, Assam, Nagaland, Arunachal Pradesh
Explanation: Regions in the northeastern part of India, especially Meghalaya (Cherrapunji and Mawsynram), receive over 200 cm of rainfall annually, making them among the wettest places on Earth.
Q4. Reading of the barometer going down is an indication of
(a) Storm
(b) Rainfall
(c) Snow
(d) Intense heat
(UPSC Prelims 1987)
Answer: (b) Rainfall
Explanation: A falling barometer reading indicates low atmospheric pressure, which is commonly associated with rainfall or stormy weather. It signals the approach of a weather disturbance.