The fastest mode of heat transfer is
1. Conduction
2. Radiation
3. Convection
4. all are equally fast
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. \(122.4\)
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 \(80^{\circ}\mathrm{C}\) \(70^{\circ}\mathrm{C}\)
1. | less than 5 minutes. |
2. | equal to 5 minutes. |
3. | more than 5 minutes. |
4. | can't say anything as the temperature of the surroundings is not known. |
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 , a fraction of its volumen= is submerged, while at temperature of a fraction is seen to be submersed. If the coefficient of volume expansion of iron is and that of mercury is , then the ratio can be expressed as:
1.
2.
3.
4.
Hot water cools from 60 to 50 in first 10 minutes and from 50 to 42 in next 10 minutes. The temperature of surrounding is :
1.
2.
3.
4.