A study of moisture in the atmosphere. The focus is on understanding the physical relationships between temperature, water vapor capacity, saturation limits (Relative Humidity), and the cooling mechanisms triggering condensation.
Given below are two statements, one is labelled as Assertion (A) and other as Reason (R) :
Assertion (A): The amount of moisture in the atmosphere is associated with latitude.
Reason (R): The ability to keep the moisture in the form of water vapour is related to temperature.
Code:
(A) and (R) are true, and (R) is the correct explanation of
(A).
Correct Answer:
(A) and (R) are true, but (R) is not the correct explanation of
Ques: 2
Humid heat is experienced in summer when the weather is:
Correct Answer:
(D)
Muggy
Humidity is the amount of water vapour in the air. The energy in form of heat required to convert water into vapour or gas, is known as humid heat. In summer, humidity is very high therefore weather is muggy. Absolute humidity is the weight of water vapour per unit volume, usually expressed in grains per cubic foot.
Ques: 3
Why are dewdrops NOT formed on a cloudy night?
Correct Answer:
(B) Clouds reflect back the Earth's radiation.
Dew : Dew is the water droplets formed by condensation of water vapour on a relatively cold surface of an object. It forms when the temperature of an object drops below the dew point temperature. When there is a cloudy weather condition, terrestrial radiation is radiated back to the earth's surface after reflection from clouds. This leads to the formation of Greenhouse condition due to which temperature on the earth's surface is relatively higher. Hence condition becomes unfavourable for the creation of dew.
Ques: 4
Given below are two statements, one is labelled as Assertion (A) and other as Reason (R) :
Assertion (A): 60o–65olatitudes in both the hemispheres have a low-pressure belt instead of high pressure.
Reason (R): The low-pressure areas are stable over oceans rather than on land.
Code:
(A) and (R) are true, and (R) is the correct explanation of
(A).
Correct Answer:
(C) is true, but (R) is false.
The sub-polar low-pressure belt lies between 60°- 65°latitude in both the hemisphere throughout the year as there is low temperature and low atmospheric pressure. Although this belt has nothing to do with temperature. Hence, assertion (A) is correct. Low atmospheric pressure generally built upon land where as high atmospheric pressure built mostly over oceans. Hence, reason (R) is incorrect.
Ques: 5
A device used to measure humidity is called a
Correct Answer:
(B) Hygrometer
A hygrometer is an instrument used to measure relative humidity. A psychrometer is an example of a hygrometer. A psychrometer uses two thermometers to measure relative humidity, one measures the dry-bulb temperature, and the other measures the wet-bulb temperature.