Q138
Which one of the following conditions is not necessary for precipitation to occur?
A.
The air must be warm
AnswerB.
The air must be saturated
C.
The air must be cooled below its dew point
D.
The air must contain hygroscopic particles
Answer: Option A
Solution
Answer: Option A
Solution:
The air may or may not be warm. Most of the condensed water in clouds does not fall as precipitation because their fall speed is not large enough to overcome updrafts which support the clouds. For precipitation to happen, first tiny water droplets must condense on even tinier dust, salt, or smoke particles, which act as a nucleus.