A copper rod of \(88\) cm and an aluminium rod of an unknown length have an equal increase in their lengths independent of an increase in temperature. The length of the aluminium rod is:
1. \(68\) cm
2. \(6.8\) cm
3. \(113.9\) cm
4. \(88\) cm
A substance is in solid form at \(0^{\circ}\mathrm{C}\). The amount of heat added to this substance and its temperature are plotted in the following graph. If the relative specific heat capacity of the solid substance is 0.5, from the graph, the specific latent heat of the melting process is: (Specific heat capacity of water = 1000 cal kg-1 K-1 )
1. 60000 cal kg-1
2. 40000 cal kg-1
3. 10000 cal kg-1
4. 20000 cal kg-1
Some water at \(0^{\circ}\mathrm{C}\) is placed in a large insulated enclosure (vessel). The water vapour formed is pumped out continuously. What fraction of the water will eventually freeze, if the latent heat of vaporization is seven times the latent heat of fusion?
1. | 7/8 | 2. | 8/7 |
3. | 3/8 | 4. | 5/8 |
On a new scale of temperature, which is linear and called the \(\mathrm{W}\) scale, the freezing and boiling points of water are \(39^\circ ~\mathrm{W}\)and \(239^\circ ~\mathrm{W}\) respectively. What will be the temperature on the new scale corresponding to a temperature of \(39^\circ ~\mathrm{C}\) on the Celsius scale?
1. \(78^\circ ~\mathrm{C}\)
2. \(117^\circ ~\mathrm{W}\)
3. \(200^\circ ~\mathrm{W}\)
4. \(139^\circ ~\mathrm{W}\)
The temperature of a body on the Kelvin scale is found to be x K. When it is measured by a Fahrenheit thermometer, it is found to be xF, then the value of x is:
1. 40
2. 313
3. 574.25
4. 301.25
Liquid oxygen at 50 K is heated up to 300 K at a constant pressure of 1 atm. The rate of heating is constant. Which one of the following graphs represents the variation of temperature with time?
1. | 2. | ||
3. | 4. |
If the radius of a star is R and it acts as a black body, what would be the temperature of the star at which the rate of energy production is Q?
1.
2.
3.
4.
A body cools from a temperature of 3T to 2T in 10 minutes. The room temperature is T. Assuming that Newton's law of cooling is applicable, the temperature of the body at the end of the next 10 minutes will be:
1.
2.
3.
4.
The rate of heat emission from an ideal black body at temperature T is H. What will be the rate of emission of heat by another body of same size at temperature 2T and emissivity 0.25?
1. | 16 H | 2. | 4 H |
3. | 8 H | 4. | 4.5 H |
Two slabs A and B of equal surface area are placed one over the other such that their surfaces are completely in contact. The thickness of slab A is twice that of B. The coefficient of thermal conductivity of slab A is twice that of B. The first surface of slab A is maintained at \(100^{\circ}\mathrm{C}\) while the second surface of slab B is maintained at \(25^{\circ}\mathrm{C}\). The temperature at the common surface will be:
1. \(62.5^{\circ}\mathrm{C}\)
2. \(45^{\circ}\mathrm{C}\)
3. \(55^{\circ}\mathrm{C}\)
4. \(85^{\circ}\mathrm{C}\)