Question

There is a spontaneous change from liquid to vapour state and back to liquid state at the point of fall of waterfall.

(a) True

(b) False

This question was posed to me in unit test.

Origin of the question is Works of Streams and Rivers topic in portion Geological Work of Water of Engineering Geology

Answer 1

Correct answer is (a) True

The explanation is: It is known that where stream velocity exceeds 12m/sec, the water pressure developed at the impinging points equals vapour pressure and there is spontaneous change from liquid to vapour state and back to liquid state at that point.