The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of a perfectly black body. This statement is known as_________________?

Related Mcqs:

1. According to Kirchoff’s law, the ratio of emissive power to absorptivity for all bodies is equal to the emissive power of a _________________?

   A. grey body B. brilliant white polished body C. red hot body D. black body E. none of the above...

2. The emissive power of a body depends upon its___________________?

   A. temperature B. wave length C. physical nature D. all of the above E. none of the above...

3. If the temperature of a solid surface changes form 27°C to 627°C, then its emissive power changes in the ratio of___________________?

   A. 3 B. 6 C. 9 D. 27 E. 81...

4. The value of the wavelength for maximum emissive power is given by ___________________?

   A. Wien’s law B. Planck’s law C. Stefan’s law D. Fourier’s law E. Kirchhoff’s law...

5. Emissivity of a white polished body in comparison to a black body is________________?

   A. higher B. lower C. same D. depends upon the shape of body E. none of the above...

6. The total emissivity power is .defined as the total amount of radiation emitted by a black body per unit_______________?

   A. temperature B. thickness C. area D. time E. area and time...

7. All radiations in a black body are___________________?

   A. reflected B. refracted C. transmitted D. absorbed E. partly reflected and partly absorbed...

8. A perfect black body is one which_______________?

   A. is black in colour B. reflects all heat C. transmits all heat radiations D. abslprbs heat radiations of all wave lengths falling on it E. fully opaque...

9. According to Stefan’s law, the total radiation from a black body per second per unit area is proportional to____________________?

   A. absolute temperature B. T2 C. T5 D. t E. l/T...

10. Depending on the radiating properties, a body will be black when_________________?

    A. p = 0, x = 0 and a = 1 B. p= l,T = 0anda = 0 C. p = 0, x = 1 and a = 0 D. x = 0, a + p = 0 E. a = 0,x + p= 1. where a = absorptivity, p == reflectivity, X = transmissivity...