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

Related Mcqs:

1. 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

2. 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

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 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

5. According to Wien’s law, the wavelength corresponding to maximum energy is proportion to ________________?

   A. absolute temperature (T)
   B. I2
   C. f
   D. t
   E. 1/r

6. Which of the following has maximum value of thermal conductivity________________?

   A. aluminium
   B. steel
   C. brass
   D. copper
   E. lead

7. Unit of thermal conductivity in M.K.S. units is ___________________?

   A. kcal/kg m2 °C
   B. kcal-m/hr m2 °C
   C. kcal/hr m2 °C
   D. kcal-m/hr °C
   E. kcal-m/m2 °C

8. Heat flowing from one side to other depends directly on ___________________?

   Pick up the wrong case?

   A. face area
   B. time
   C. thickness
   D. temperature difference
   E. thermal conductivity

9. Which of the following is the case of heat transfer by radiation ___________________?

   A. blast furnace
   B. heating of building
   C. cooling of parts in furnace
   D. heat received by a person from fireplace
   E. all of the above

10. According to Prevost theory of heat exchange ___________________?

    A. it is impossible to transfer heat from low temperature source to t high temperature source
    B. heat transfer by radiation requires no medium
    C. all bodies above absolute zero emit radiation
    D. heat transfer in most of the cases takes place by combination of conduction, convection and radiation
    E. rate of heat transfer depends on thermal conductivity and temperature difference