Physics questions
20027 published questions with worked solutions.
- Behaviour of an ideal black body is similar to [RAS 1999]
- A black body emits radiations of maximum intensity at a wavelength of 5000 Å, when the temperature of the body is 1227℃. If the...
- On observing light from three different stars P, Q and R, it was found that intensity of violet colour is maximum in the spectrum...
- A piece of iron is heated in a flame. It first becomes dull red then becomes reddish yellow and finally turns to white hot. The...
- A black body has maximum wavelength _m at temperature 2000 K. Its corresponding wavelength at temperature 3000 K will be
- A black body radiates heat at temperature 'T_1' and 'T_2' (T_2 > T_1). The frequency corresponding to maximum energy is [MH-CET...
- Suppose the sun expands so that its radius becomes 100 times its present radius and its surface temperature becomes half of its...
- If the temperature of the sun were to be increased from T to 2T and its radius from R to 2R, then the ratio of the radiant energy...
- Three objects coloured black, gray and white can withstand hostile conditions up to 2800℃. These objects are thrown into a...
- Rates of emission of heat by perfectly black body maintained at ratio 27℃ and 927℃ are in ratio
- A black body radiates 20 W at temperature 227℃. If temperature of the black body is changed to 727℃, then its radiating power...
- A black body at a temperature of 227℃ radiates heat energy at the rate of 5 cal/cm²-second. At a temperature of 727℃, the rate of...
- A black body at 227℃ radiates heat at the rate of 7 cal/cm² s. At a temperature of 727℃, the rate of heat radiated in the same...
- A metal ball of surface area 200 cm² and temperature 527℃ is surrounded by a vessel at 27℃. If the emissivity of the metal is...
- Emissive power of a black body at a temperature 300 K is 81 J ,m^ -2 ,s^ -1 . Another one is an ordinary body having emissivity...
- Two spheres P and Q of same colour having radii 8 cm and 2 cm kept at temperature 127℃ and 527℃ respectively. The ratio of the...
- A body radiates heat at the rate of 5 cal ,m^ -2 ,s^ -1 when its temperature is 227℃. The heat radiated by the same body when its...
- Two spherical black bodies of radii r_1 and r_2 and with surface temperature T_1 and T_2 respectively radiate the same power....
- Rate of loss of heat of two spheres at same temperature having radii in ratio 1 : 2 is
- Parallel rays of light of intensity I = 912 W ,m^ -2 are incident on a spherical black body kept in surroundings of temperature...