# Properties of Solids and Liquids

### Work done in increasing the size of a soap bubble

Work done in increasing the size of a soap bubble from a radius of 3 cm to 5 cm is nearly. (Surface tension of soap solution = 0.03 Nm-1)

1. 0.2π mJ
2. 0.4π mJ
3. 2π mJ
4. 4π mJ

### 100 g of water is heated from 30°C to 50°C

100 g of water is heated from 30°C to 50°C ignoring the slight expansion of the water, the change in its internal energy is (specific heat of water is 4184 J/Kg/K)

1. 2.1 kJ
2. 4.2 kJ
3. 8.4 kJ
4. 84 kJ

### The pressure that has to be applied to the ends of a steel wire

The pressure that has to be applied to the ends of a steel wire of length 10 cm to keep its length constant when its temperature is raised by 100°C is: (For steel, Young’s modulus is 2×1011 N m–2 and coefficient of thermal expansion is 1.1×10-5 K-1)

1. 2.2 × 106 Pa
2. 2.2 × 107 Pa
3. 2.2 × 108 Pa
4. 2.2 × 109 Pa

### Water is flowing continuously from a tap having an internal diameter

Water is flowing continuously from a tap having an internal diameter 8×10-3 m. The water velocity as it leaves the tap is 0.4 ms-1. The diameter of the water stream at a distance 2×10-1 m below the tap is close to

1. 7.5 × 10-3 m
2. 9.6 × 10-3 m
3. 3.6 × 10-3 m
4. 5.0 × 10-3 m

### If mass-energy equivalence is taken into account

If mass-energy equivalence is taken into account, when water is cooled to form ice, the mass of water should

1. first increase then decrease
2. increase
3. decrease
4. remain unchanged

### A cylinder of height 20 m is completely filled with water. The velocity of efflux of water

A cylinder of height 20 m is completely filled with water. The velocity of efflux of water (in ms-1) through a small hole on the side wall of the cylinder near its bottom is

1. 20
2. 25.5
3. 10
4. 5

### The flow rate of water from a tap of diameter 1.25 cm is 0.48 L/min

The flow rate of water from a tap of diameter 1.25 cm is 0.48 L/min. The coefficient of viscosity of water is 10-3 Pa s. After sometime the flow rate is increased to 3 L/min. Characterize the flow for both the flow rates.

### If it takes 5 minutes to fill a 15 litre bucket from a water tap of diameter

If it takes 5 minutes to fill a 15 litre bucket from a water tap of diameter 2/√π cm then the Reynolds number for the flow is (density of water = 103 kg/m3 and viscosity of water = 10-3 Pa.s) close to:

1. 5500
2. 11,000
3. 550
4. 1100