A. temperature
B. wave length
C. physical nature
D. all of the above
E. none of the above
Related Mcqs:
- 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_________________?
A. Krichoff’s law
B. Stefan’s law
C. Wien’ law
D. Planck’s law
E. Black body law - 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 - 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 - 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 - When heat is transferred form hot body to cold body, in a straight line, without affecting the intervening medium, it is referred as heat transfer by __________________?
A. conduction
B. convection
C. radiation
D. conduction and convection
E. convection and radiation - 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 - 40% of incident radiant energy on the surface of a thermally transparent body is reflected back. If the transmissivity of the body be 0.15, then the emissivity of surface is____________________?
A. 0.45
B. 0.55
C. 0.40
D. 0.75
E. 0.60 - 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 - Thermal conductivity of wood depends on_______________?
A. moisture
B. density
C. temperature
D. all of the above
E. none of the above - The amount of radiation mainly depends on___________________?
A. nature of body
B. temperature of body
C. type of surface of body
D. all of the above
E. none of the above
