Physics questions
20027 published questions with worked solutions.
- A shining 500 W bulb behaves like a black body because
- The area under the curve drawn between E_ and for a body is proportional to
- The radiation energy density per unit wavelength at a temperature T has a maximum at a wavelength _0. At temperature 2T, it will...
- If the emissive and absorptive powers of a body are E and A respectively at temperature T, then the emissive power of a black...
- Three bodies A, B and C have equal area which are painted red, yellow and black respectively. If they are at same temperature,...
- The rate of emission of electromagnetic energy by any body does not depend on
- S.I. unit of emissive power is
- Coefficient of emission of a surface does NOT depend on
- Emissivity of perfectly black body is
- For a perfectly black body, its absorptive power is
- The ratio of emissive power in all the bodies at a given wavelength and a fixed temperature to that of a perfect black body at...
- The emissive power of a body does not depend upon _______ of the body
- Dimensions of emissive power are
- Coefficient of emission or emissivity (e) is defined as
- At temperature T, the emissive power and absorption power of a body for certain wavelength are e_ and a_ respectively, then
- In M.K.S. system, Stefan's constant is denoted by . In C.G.S. system multiplying factor of will be
- If a sphere, cube and thin plate are heated and then kept in the same surrounding, the one which cools first is
- The law which relates the energy radiated per second by unit area of a body and fourth power of absolute temperature of body is
- One black body at temperature T is surrounded by another black body at temperate T_1 (T_1 < T). At T, the radiation emitted by...
- The amount of radiation emitted by a perfectly black body is proportional to