Mechanical Properties of Fluids · Question 7

A tub is filled with water and a wooden cube 10 cm 10 cm 10 cm is placed in the water. The wooden cube is found to float on the water with a part of it submerged in water. When a metal coin is placed on the wooden cube, the submerged part is increased by 3.87 cm. The mass of the metal coin is gram. (Take water density as 1 g/cm3 and density of wood as 0.4 g/cm3)

The surface tension of a soap bubble is 0.03 N/m. The work done in increasing the diameter of bubble from 2 cm to 6 cm is 10-4 J. The value of is . (Take =3.14)

1. 0.86
2. 0.64
3. 1.92
4. 7.68

If an air bubble of diameter 2 mm rises steadily through a liquid of density 2000 kg/m3 at a rate of 0.5 cm/s, then the coefficient of viscosity of liquid is Poise. (Take g=10 m/s2)

1. 0.88
2. 8.8
3. 88.8
4. 0.088

Sixty four raindrops of radius 1 mm each falling down with a terminal velocity of 10 cm/s coalesce to form a bigger drop. The terminal velocity of bigger drop is cm/s.

A cubical block of density b = 600 kg/m3 floats in a liquid of density l = 900 kg/m3. If the height of block is H = 8.0 cm, then height of the submerged part is cm.

1. 6.3
2. 4.3
3. 7.3
4. 5.3

A soap bubble of surface tension 0.04 N/m is blown to a diameter of 7 cm. If (15000 - x) of work is done in blowing it further to make its diameter 14 cm, then the value of x is . ( = 22/7)

A small metallic sphere of diameter 2 mm and density 10.5 g/cm3 is dropped in glycerine having viscosity 10 Poise and density 1.5 g/cm3 respectively. The terminal velocity attained by the sphere is cm/s. ( = 227 and g = 10 m/s2)

1. 1.0
2. 1.5
3. 3.0
4. 2.0

A cylindrical tube AB of length l, closed at both ends contains an ideal gas of 1 mol having molecular weight M. The tube is rotated in a horizontal plane with constant angular velocity about an axis perpendicular to AB and passing through the edge at end A, as shown in the figure. If PA and PB are the pressures at A and B respectively, then (Consider the temperature is same at all points in the tube) [figure]

1. PB = PA e ( M 2 l23RT )
2. PB = PA
3. PB = PA e ( M 2 l22RT )
4. PB = PA e ( M 2 l2RT )

Given below are two statements : In the light of the above statements, choose the correct answer from the options given below

1. Statement I is false but Statement II is true
2. Statement I is true but Statement II is false
3. Both Statement I and Statement II are false
4. Both Statement I and Statement II are true

When a part of a straight capillary tube is placed vertically in a liquid, the liquid rises up to certain height h. If the inner radius of the capillary tube, density of the liquid and surface tension of the liquid decrease by 1% each, then the height of the liquid in the tube will change by %.

1. +3
2. +1
3. -1
4. -3