A person weighing 60 kg taken in 2000 kcal diet in a day. If this energy were to be used in heating the person without any losses, what would be his rise in temperature ? (sp. heat of human body is 0.83 cal/gm/o C )
40.16o C
44.23o C
49.99o C
47.23o C
For a gas, the difference between two principal specific heats is 4150 J kg-1 K-1 . What is the specific heat of the gas at constant volume if the ratio of specific heats is 1.4 ?
5186 J kg-1 K-1
10375 J kg-1 K-1
1060 J kg-1 K-1
8475 J kg-1 K-1
Heat capacity of a body is infinite. It means
heat is given out
heat is taken in
no change in temperature whether heat is taken in or given out
All of these
If the temperature of the sun increases from T to 2T and its radius from R to 2R, then the ratio of the radiant energy received on earth to what it was previously, will be :
4
16
32
64
The graph shown in the adjacent diagram, represents the variation of temperature (T) of two bodies X and Y having the same surface area, with time (t) due to the emission of radiation. Find the correct relation between the emissivity and absorptivity power of the two bodies ?
eX < eY and aX > aY
eX > eY and aX > aY
eX < eY and aX < aY
Heat given to a body, which raises its temperature by 1oC is :
Water equivalent
Temperature gradient
Thermal capacity
Specific heat
If the temperature of the sun is doubled, the rate of energy received on earth will be increased by a factor of
2
8
Compared to burn due to air at 100oC, a burn due to steam at 100oC is :
More dangerous
Less dangerous
Equally dangerous
Can't be predicted
A metal ball immersed in alcohol weighs W1 at 0oC and W2 at 50oC. The co-efficient of cubical expansion of the metal is less than that of the alcohol. Assuming that the density of the metal is large compared to that of alcohol, it can be shown that :
W1 > W2
W1 = W2
W1 < W2
W1 << W2
Two spheres of the same material have radii 1 m and 4 m and temperatures 4,000 K and 2,000 K respectively. The ratio of the energy radiated per second by the first sphere to that by the second is :
1 : 1
1 : 9
4 : 1
16 :1