A 10 kW drilling machine is used to drill a bore in a small aluminium block of mass 8.0 kg. How much is the rise in temperature of the block in 2.5 minutes?
(Assuming 50% of power is used up in heating the machine itself or lost to the surroundings? Specific heat of aluminium $=0.91 J g^{-1} K^{-1}$.)
1. 103°C
2. 109°C
3. 211°C
4. 197°C

In an experiment on the specific heat of a metal, a 0.20 kg block of the metal at \(150^{\circ}\mathrm{C}\) is dropped in a copper calorimeter (of water equivalent of 0.025 kg) containing 150 \(c m^{3}\) of water at \(27^{\circ}\mathrm{C}\). The final temperature is \(40^{\circ}\mathrm{C}\). The specific heat of the metal will be: (Heat   losses   to   the   surroundings   are   negligible)
1. \(0 . 40  ~ \text{Jg}^{- 1} \text{K}^{- 1}\)
2. \(0 . 43  ~ \text{Jg}^{- 1} \text{K}^{- 1}\)
3. \(0 . 54 ~ \text{Jg}^{- 1} \text{K}^{- 1}\)
4. \(0 . 61 ~ \text{Jg}^{- 1} \text{K}^{- 1}\)

A copper block of mass 2.5 kg is heated in a furnace to a temperature of 500 °C and then placed on a large ice block. What is the maximum amount of ice that can melt?

(Specific heat of copper = $0.39 J g^{-1} K^{-1},$ the heat of fusion of water = 335 J/g)

1. 1.32 kg
2. 1.12 kg
3. 1.45 kg
4. 1.53 kg

Temperature is a measure of:

1. Hotness or coldness

2. Heat possessed by a body

3. Potential energy

4. Thermal energy

If in the winter season, the surface temperature of the lake is $1°\mathrm{C}$, the temperature at the bottom of the lake will be:

1. $1°\mathrm{C}$

2. $0°\mathrm{C}$

3. $4°\mathrm{C}$

4. All values less than $1°\mathrm{C}$ are possible.

The readings of a bath on Celsius and Fahrenheit thermometers are in the ratio of 2: 5. The temperature of the bath is:

1. $-26.66°\mathrm{C}$

2. $40°\mathrm{C}$

3. $45.71°\mathrm{C}$

4. $26.66°\mathrm{C}$

A hole is drilled in a copper sheet. The diameter of the hole is 4.24 cm at $27.0°\mathrm{C}$. The diameter of the hole, when it is heated to 35.0 °C, is:

1. less than 4.24 cm.

2. equal to 4.24 cm.

3. more than 4.24 cm.

4. Data insufficient

On heating, a uniform metallic cylinder length increases by 3%. The area of cross-section of its base will increase by:

1. 1.5%

2. 3%

3. 9%

4. 6%

A circular metallic disc of radius R has a small circular cavity of radius r as shown in the figure. On heating the system,

1. R increases and r decreases.

2. R decreases and r increases.

3. Both R and r increases.

4. Both R and r decreases.

A uniform copper rod of length 50 cm and diameter 3.0 mm is kept on a frictionless horizontal surface at 20 °C. The coefficient of linear expansion of copper is $2.0\times {10}^{-5} {\mathrm{K}}^{-1}$ and Young's modulus is $1.2\times {10}^{11} \mathrm{N}/{\mathrm{m}}^2$. The copper is heated to 100°C, then the tension developed in the copper rod is:

1. $12\times {10}^3 \mathrm{N}$

2. $36\times {10}^3 \mathrm{N}$

3. $18\times {10}^3 \mathrm{N}$

4. Zero