26339.A person with dark skin as compared to a person with white skin will experience
Less heat and less cold
More heat and more cold
More heat and less cold
Less heat and more cold.
26341.For a given body at a particular temperature, its coefficients of reflection and transmission are 0.63 and 0.21 respectively. Then its coefficient of emission at the same temperature will be
0.16
0.32
0.84
0.36
26342.A body of surface area 25 × 10-3 m2 emits 0.4 Kcal of heat in 20 s at 50°C. What is the emissive power of the body at that temperature?
0.5 Kcal/m2/S
0.6 Kcal/m2/S
0.7 Kcal/m2/S
0.8 Kcal/m2/S
26344.The solar constant for the earth is about 1.8 J/m2/S. what is the solar constant for a black body situated on a planet which is situated at a distance of 0.3 times the distance of the earth from the sun?
9 J/m2/S
12 J/m2/S
15 J/m2/S
20 J/m2/S
26345.The velocity of thermal radiation (V) is related to the velocity of light (C) as
V > C
V < C
V = $\dfrac{C}{2}$
V = C
26346.512 calories of radiation is incident on a body. It absorbs 220 calories the coefficient of emission is
0.43
0.57
1.7
0.34
26348.A liquid takes 5 minutes to cool from 80°C to 50°C. how much time it will take to cool from 60°C to 30°C, if the temperature of the surrounding is 20°C?
5 minutes
7 minutes
9 minutes
12 minutes