Condensation of water vapour into water is influenced by which of the following factor/factors? 1. Volume of air 2. Humidity 3. Temperature Select the answer using the code given below:
- (a)1 only
- (b)1 and 2 only
- (c)2 and 3 only
- (d)1, 2 and 3
Correct — D, 1, 2 and 3. Condensation is the change of water vapour into liquid water, and standard geography (NCERT, Water in the Atmosphere) lists the factors that control it as the volume of air, temperature, atmospheric pressure and humidity. Of the three items given, all apply: cooling (temperature) is what usually triggers condensation, humidity fixes how much vapour is present relative to saturation, and the volume of air affects how the vapour concentrates and cools. So statements 1, 2 and 3 are all correct.
- (a)1 only — Too narrow. Volume of air does matter, but temperature and humidity are the most direct controls on condensation, so restricting the answer to statement 1 alone is wrong.
- (b)1 and 2 only — Leaves out temperature (statement 3), which is the primary driver of condensation — air must usually be cooled to its dew point for vapour to condense.
- (c)2 and 3 only — Drops the volume of air (statement 1), which the standard list of controlling factors includes, so this pairing is incomplete.
Condensation is the process by which water vapour in the air turns into liquid water once the air is cooled to its dew point (the temperature at which it becomes saturated). It gives rise to dew, fog, mist and cloud. The factors that influence it are the volume of air, temperature, atmospheric pressure and humidity.
The question just asks which of the listed items influence condensation. Because temperature (cooling to dew point), humidity (how near saturation the air is) and the volume of air are all in the standard NCERT list of controlling factors, every statement qualifies. When all listed factors are genuine controls, the 'all of the above' code is the answer.
- Condensation = water vapour changing into liquid water at or below the dew point.
- Factors influencing it: volume of air, temperature, atmospheric pressure and humidity.
- Cooling air to its dew point (saturation) is the usual trigger for condensation.
- Forms of condensation include dew, fog, mist, frost and clouds.
All three listed factors influence condensation, so the answer is (d) 1, 2 and 3.
- Dropping 'volume of air' because it feels less obvious than temperature and humidity.
- Assuming only temperature matters — humidity and air volume are part of the standard list.
Atmospheric-moisture questions test the list of controlling factors or the definition of dew point — learn both.
No directly related past PYQ was found.
- practice — not a real PYQ
The temperature at which air becomes saturated and condensation begins is called the
- (a)Boiling point
- (b)Dew point
- (c)Freezing point
- (d)Lapse rate
Answer(b) Dew point — the temperature at which air is saturated and vapour starts to condense.
- practice — not a real PYQ
Which of the following is a form of condensation?
- (a)Evaporation
- (b)Transpiration
- (c)Fog
- (d)Sublimation of ice to vapour
Answer(c) Fog — tiny water droplets formed when moist air near the ground is cooled below its dew point.