# Fluid Mechanics

## The hydraulic press shown in figure is used to raise the mass M through a height of 4.0 mm by performing 400 J of work at the small piston….

Q: The hydraulic press shown in figure is used to raise the mass M through a height of 4.0 mm by performing 400 J of work at the small piston. The diameter of the large piston is 8 cm while that of smaller one is 2 cm. the mass M is of value n × 104 kg. What is the value of n ? (g = 10 m/s2) (a) 1

(b) 2

(c) 3

(d) 4

Ans: (a)

## The vessel shown in Fig. has two sections of area of cross-section A1 and A2 . A liquid of density ρ fills both the sections, upto height h in each

Q: The vessel shown in Fig. has two sections of area of cross-section A1 and A2 . A liquid of density ρ fills both the sections, upto height h in each. Neglecting atmospheric pressure, (a) The pressure at the base of the vessel is 2 h ρ g

(b) The weight of the liquid in vessel is equal to 2 h ρ g

(c) The force exerted by the liquid on the base of vessel is 2 h ρ g A2

(d) The walls of the vessel at the level X exert a force h ρ g(A2 – A1 )downwards on the liquid

Ans: (a) , (c) , (d)

## A cylindrical vessel is filled with equal amounts by weights of mercury and water. The total height of the two layers is 29.2 cm. The pressure of the liquid…

Q: A cylindrical vessel is filled with equal amounts by weights of mercury and water. The total height of the two layers is 29.2 cm. The pressure of the liquid at the bottom of the vessel is: (specific gravity of mercury is 13.6)

(a) 8 cm of Hg

(b) 6 cm of Hg

(c) 4 cm of Hg

(d) 2 cm of Hg

Ans: (c)

## To what height should a cylindrical vessel to filled with a homogeneous liquid to make the force with which the liquid presses on the sides of the vessel equal to…

Q: To what height should a cylindrical vessel to filled with a homogeneous liquid to make the force with which the liquid presses on the sides of the vessel equal to the force exerted by the liquid on the bottom of the vessel. It should be

Ans: (a)

## A U-tube is partially filled with water. oil which does not mix with water is next poured into one side until water rises by 25 cm on the other side….

Q: A U-tube is partially filled with water. oil which does not mix with water is next poured into one side until water rises by 25 cm on the other side, if the density of oil be 0.8, the oil level will stand higher than the water level by:

(a) 6.25 cm

(b) 12.50 cm

(c) 31.25 cm

(d) 62.50 cm