A. radiant heat is proportional to fourth power of absolute temperature
B. emissive power depends on temperature
C. emissive power and absorptivity are constant for all bodies
D. ratio of emissive power to absorptive power is maximum for perfectly black body
E. ratio of emissive power to absorptive power for all bodies is same and is equal to the emissive power of a perfectly black body
Heat Transfer
Heat Transfer
A. better insulation should be put over pipe and better one over it
B. inferior insulation should be put over pipe and better one over it
C. both may be put in any order
D. whether to put inferior OIL over pipe or the better one would depend on steam temperature
E. unpredictable
A. cold water inlet and outlet
B. hot medium inlet and outlet
C. hot medium outlet and cold water inlet
D. hot medium outlet and cold water outlet
E. none of the above
A. Grashoff number
B. Nusselt number
C. Weber number
D. Prandtl number
E. Reynold number
A. higher
B. lower
C. same
D. depends upon the shape of body
E. none of the above
A. 1 :1
B. 2: 1
C. 1 : 2
D. 4 : 1
E. 1 : 4
A. thermal resistance
B. thermal coefficient
C. temperature gradient
D. thermal conductivity
E. heat-transfer
A. varies with temperature
B. varies with wavelength of the incident ray
C. is equal to its emissivity
D. does not vary with temperature and. wavelength of the incident ray
E. none of the above
A. emissivity
B. transmissivity
C. reflectivity
D. intensity of radiation
E. absorptivity
A. convection
B. radiation
C. conduction
D. both convection and conduction
E. none of the above
