A. 1 to 100
B. 0.5 to 50
C. 10 to 100
D. 100 to 1000
Related Mcqs:
- The range of electromagnetic spectrum important in heat transfer by radiation is ______________ microns?
A. 0.38-0.78
B. 0.5-50
C. 100-1000
D. 5-50 - The absorptivity of a grey body at a given temperature _____________ with increasing wavelength of radiation?
A. Increases
B. Decreases
C. Remain constant
D. May increase or decrease; depends on the material - A perfect black body is a perfect _____________ of radiation?
A. Absorber
B. Emitter
C. Both A. & B.
D. Neither A. nor B. - Radiation heat losses from satisfactorily insulated high pressure boiler may be about _____________ percent?
A. 1
B. 7
C. 18
D. 26 - A black body when hot, emits heat radiation of _____________ wavelengths?
A. Small
B. Large
C. All
D. One fixed - Kirchoff‟s law applies to _____________ radiation?
A. Total
B. Monochromatic
C. Both A. & B.
D. Neither A. nor B. - If heat transfer rate varies with the time, it is termed as__________________?
A. Forced convection
B. Steady state conduction
C. Monochromatic radiation
D. None of these - The Sieder-Tate correlation for heat transfer in turbulent flow in pipe gives Nu α Re0.8, where, Nu is the Nusselt number and Re is the Reynolds number for the flow. Assuming that this relation is valid, the heat transfer co-efficient varies with the pipe diameter D. as _________________?
A. D-1.8
B. D-0.2
C. D0.2
D. D1.8 - With increase in the distance between the heat source and the object receiving the heat, the radiation heat transfer ?
A. Decreases
B. Increases
C. Increases exponentially
D. Remain unaffected - Radiation heat transfer rates does not depend upon the_________________?
A. Type of absorbing surface
B. Distance between the heat source and the object receiving the heat
C. Surface area and temperature of the heat source
D. None of these
