One kilogram of ice at $0°$C is mixed with one kilogram of water at 80$°C$. The final temperature of the mixture is (Take: Specific heat of water = 4200 J $k{g}^{-1}{C}^{-1}$, Latent heat of ice = 336 kJ $k{g}^{-1}$)

(1) $0°$C              (2) $50°C$

(3) $40°C$           (4) $60°C$

The fastest mode of heat transfer is 

1.  Conduction

2.  Radiation

3.  Convection

4.  all are  equally fast

A temperature of 100 ^oF (Fahrenheit scale) is equal to T K (Kelvin scale). The value of T is:

1.  310.9

2.  37.8

3.  100

4.  122.4

A black body at temperature 300K radiates heat at the rate E. If its temperature is increased by 600K, the rate of radiation will increase to -

1.  16E

2.  64E

3.  81E

4.  256E

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

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 graph correctly represents the variation of T?

1.		2.
3.		4.

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

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

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.  $20°\mathrm{C}$

A pendulum clock runs faster by 5 seconds per day at 20 ^oC and goes slow by 10 second per day at 35 ^oC. It shows the correct time at a temperature of:

1.  27.5 ^oC

2.  25 ^oC

3.  30 ^oC

4.  33 ^oC