A constrained steel rod of length \(l\), area of cross-section \(A\), Young's modulus \(Y\) and coefficient of linear expansion \(\alpha\)$$ is heated through \(t^{\circ}\text{C}\)$$. The work that can be performed by the rod when heated is:
1. \((YA\alpha t)(l\alpha t)\)
2. \(\frac{1}{2}(YA\alpha t)(l\alpha t)\)
3. \(\frac{1}{2}(YA\alpha t)\frac{1}{2}(l\alpha t)\)
4. \(2(YA\alpha t)(l\alpha t)\)

The temperature of a body on Kelvin scale is found to be X K. When it is measured by a Fahrenheit thermometer, it is found to be X⁰F. Then X is

(1) 301.25

(2) 574.25

(3) 313

(4) 40

A pendulum clock runs faster by \(5\) s per day at \(20^{\circ}\mathrm {C}\) and goes slow by \(10\) s per day at \(35^{\circ}\mathrm {C}\). It shows the correct time at a temperature of:
1. \(27.5^{\circ}\mathrm {C}\)
2. \(25^{\circ}\mathrm {C}\)
3. \(30^{\circ}\mathrm {C}\)
4. \(33^{\circ}\mathrm {C}\)

Hot water cools from 60$°\mathrm{C}$ to 50$°\mathrm{C}$ in first 10 minutes and from 50$°\mathrm{C}$ to 42$°\mathrm{C}$ in next 10 minutes. The temperature of surrounding is :

1.  $5° \mathrm{C}$

2.  $10° \mathrm{C}$

3.  $15° \mathrm{C}$

4.  $20°\mathrm{C}$

When a block of iron floats in Hg at $0°C$, a fraction $K_1$ of its volumen= is submerged, while at temperature of $60°C$ a fraction $K_2$ is seen to be submersed. If the coefficient of volume expansion of iron is ${\gamma }_{Fe}$ and that of mercury is ${\gamma }_{Hg}$, then the ratio $\frac{K_1}{K_2}$ can be expressed as:

1. $\frac{1+60{\gamma }_{Fe}}{1+60{\gamma }_{Hg}}$

2. $\frac{1-60{\gamma }_{Fe}}{1+60{\gamma }_{Hg}}$

3. $\frac{1+60{\gamma }_{Fe}}{1-60{\gamma }_{Hg}}$

4. $\frac{1+60{\gamma }_{He}}{1-60{\gamma }_{Fe}}$

Heat capacity is equal to the product of:

1.  mass and gas constant

2.  mass and specific heat

3.  latent heat and volume of water

4.  mass and Avogadro number

If \(\lambda_m\) is the wavelength, corresponding to which the radiant intensity of a block is at its maximum and its absolute temperature is \(T,\) then which of the following graphs correctly represents the variation of \(T?\)

1.		2.
3.		4.

A body cools down from \(80^{\circ}\mathrm{C}\) $\mathrm{to}$ \(70^{\circ}\mathrm{C}\) in 5 minutes. The temperature of the same body will fall from \(70^{\circ}\mathrm{C}\)$\mathrm{}$ $\mathrm{to}$ \(60^{\circ}\mathrm{C}\)$\mathrm{}$ in:

A temperature of \(100^{\circ}\text {F}\) (Fahrenheit scale) is equal to \(T~\text{K}\) (Kelvin scale). The value of \(T\) is:
1. \(310.9\)
2. \(37.8\)
3. \(100\)
4. \(122.4\)