(English Medium) ICSE Class 9 - CISCE Question Bank Solutions

A tall vertical cylinder filled with water is kept on a horizontal table top. Two small holes A and B are made on the wall of the cylinder, A near the middle and B just Below the free surface of water. State and explain your observation.

How does the liquid pressure on a diver change if:

the diver moves to the greater depth

How does the liquid pressure on a diver change if : 

The diver moves horizontally?

The diagram below in Fig. 4.12 shows a device which makes the use of the principle of transmission of pressure.

1. Name the parts labelled by the letters X and Y.
2. Describe what happens to valves A and B and to the quantity of water in the two cylinders when the lever arm is moved down.
3. Give reasons for what happens to valves A and B in part (ii).
4. What happens when the release valve is opened?
5. What happens to valve B in cylinder P when the lever arm is moved up?
6. Give a reason for your answer in part (v).
7. State one use of the above device.

Complete the following sentence :

Pressure at a depth h in a liquid of density p is ......................

Complete the following sentence :

 Pressure is .................... in all directions about a point in a liquid.

Complete the following sentence :

Pressure at all points at the same depth is ....................

Complete the following sentence :

Pressure at a point inside the liquid is ...................... To its depth.

Complete the following sentence :

Pressure of a liquid at a given depth is .................. To the density of the liquid.

The S.I. unit of pressure is : 

The pressure inside a liquid of density p at a depth h is : 

The pressure P₁ at a certain depth in river water and P₂ at the same depth in sea water are related as :

The pressure P₁ at the top of a dam and P₂ at a depth h form the top inside water (density p) are related as : 

A hammer exerts a force of 1.5 N on each of the two nails A and B. The area of cross section of tip of nail A is 2 mm² while that of nail B is 6 mm². Calculate pressure on each nail in pascal.

A block of iron of mass 7.5 kg and of dimensions 12 cm × 8 cm × 10 cm is kept on a table top on its base of side 12 cm × 8 cm.

Calculate:

1. Thrust and
2. Pressure exerted on the table top

Take 1 kgf = 10 N.

A vessel contains water up to a height of 1.5 m. Taking the density of water 10³ kg m^-3, acceleration due to gravity 9.8 m s^-2 and area of base of vessel 100 cm², calculate: (a) the pressure and (b) the thrust at the base of vessel.

The area of base of a cylindrical vessel is 300 cm². Water (density= 1000 kg m^-3) is poured into it up to a depth of 6 cm. Calculate : (a) the pressure and (b) the thrust of water on the base. (g = 10m s^-2.

1. Calculate the height of a water column which will exert on its base the same pressure as the 70 cm column of mercury. Density of mercury is 13.6 g cm^-3.
2. Will the height of the water column in part (a) change if the cross-section of the water column is made wider?

The pressure of water on the ground floor is 40,000 Pa and on the first floor is 10,000 Pa. Find the height of the first floor. (Take : density of water = 1000 kg m^-3, g = 10 m s^-2)

A simple U tube contains mercury to the same level in both of its arms. If water is poured to a height of 13.6 cm in one arm, how much will be the rise in mercury level in the other arm?

Given : density of mercury = 13.6 x 10³ kg m^-3 and density of water = 10³ kg m^-3.