Mechanical Properties of Fluids · Question 7

The amount of energy required to form a soap bubble of radius 2 cm from a soap solution is nearly: (surface tension of soap solution = 0.03 N m-1)

1. 5.06 10-4 J
2. 3.01 10-4 J
3. 50.1 10-4 J
4. 30.16 10-4 J

The venturi-meter works on :

1. Bernoulli's principle
2. The principle of parallel axes
3. The principle of perpendicular axes
4. Huygens' principle

A spherical ball is dropped in a long column of a highly viscous liquid. The curve in the graph shown, which represents the speed of the ball (v) as a function of time (t) is [figure]

1. A
2. B
3. C
4. D

If a soap bubble expands, the pressure inside the bubble

1. Decreases
2. Increases
3. Remains the same
4. Is equal to the atmospheric pressure

Two copper vessels A and B have the same base area but of different shapes. A takes twice the volume of water as that B requires to fill upto a particular common height. Then the correct statement among the following is :

1. Vessel B weighs twice that of A.
2. Pressure on the base area of vessels A and B is same.
3. Pressure on the base area of vessels A and B is not same.
4. Both vessels A and B weigh the same.

The terminal velocity of a copper ball of radius 5 mm falling through a tank of oil at room temperature is 10 cm s-1. If the viscosity of oil at room temperature is 0.9 kg m-1 s-1, the viscous drag force is :

1. 4.23 10-6 N
2. 8.48 10-3 N
3. 8.48 10-5 N
4. 4.23 10-3 N

The velocity of a small ball of mass M and density d, when dropped in a container filled with glycerin becomes constant after some time. If the density of glycerin is d2, then the viscous force acting on the ball will be :

1. 2Mg
2. Mg2
3. Mg
4. 32Mg

A capillary tube of radius r is immersed in water and water rises in it to a height h. The mass of the water in the capillary is 5 g. Another capillary tube of radius 2r is immersed in water. The mass of water that will rise in this tube is :

1. 5.0 g
2. 10.0 g
3. 20.0 g
4. 2.5 g

A small hole of area of cross-section 2 mm2 is present near the bottom of a fully filled open tank of height 2 m. Taking g = 10 m/s2, the rate of flow of water through the open hole would be nearly :

1. 8.9 10-6 m3/s
2. 2.23 10-6 m3/s
3. 6.4 10-6 m3/s
4. 12.6 10-6 m3/s

A soap bubble, having radius of 1 mm, is blown from a detergent solution having a surface tension of 2.5 10-2 N/m. The pressure inside the bubble equals the pressure at a point Z0 below the free surface of water in a container. Taking g = 10 m/s2, density of water = 103 kg/m3, the value of Z0 is :

1. 1 cm
2. 10 cm
3. 100 cm
4. 0.5 cm