Heat Transfer

A. absorptive power
B. emissive power
C. absorptivity
D. emissivity
E. none of the above

A. nature of body
B. temperature of body
C. type of surface of body
D. all of the above
E. none of the above

A. at all temperatures
B. at one particular temperature
C. when system is under thermal equi-librium
D. at critical temperature
E. for a polished body

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

A. convection
B. free convection
C. forced convection
D. radiation
E. radiation and convection

A. direct mixing of hot and cold fluids
B. a complete separation between hot and cold fluids
C. flow of hot and cold fluids alternately over a surface
D. generation of heat again and again
E. indirect transfer

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

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

A. black bodies
B. polished bodies
C. all coloured bodies
D. all of the above
E. none of the above

A. varies with temperature
B. varies with the wave length of incident ray
C. varies with both
D. does not vary with temperature and wave length of the incident ray
E. there is no such criterion