A steel ball is dropped in oil, then ______________.

(a)

the ball attains constant velocity after some time

(b)

the ball slopes

(c)

the speed of ball will escape on increasing

(d)

none of the above

An aeroplane gets its upward lift due to phenomenon described by the _____________.

(a)

archimedes principle

(b)

bernoulli's principle

(c)

buoyancy

(d)

pascal law

The rate of flow of liquid through an orifice of a tank does not depend upon ____________.

(a)

the size of orifice

(b)

density of liquid

(c)

height of fluid column

(d)

acceleration due to gravity

A rectangular vessel when full of water, takes 10 min to be emptied through an orifice in its bottom, how much time will it take to be emptied when half filled with water _____________.

(a)

9 min

(b)

7 min

(c)

5 min

(d)

3 min

One large soap bubble of diameter D breakes into 27 bubbles having surface tension T, the change in surface energy is _______________.

(a)

2ㅠTD²

(b)

4ㅠ TD²

(c)

ㅠ TD²

(d)

8ㅠ TD²