Category: Heat Transfer

A. higher
B. lower
C. same
D. depends upon the shape of body
E. none of the above

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

where a = absorptivity, p = reflectivity, x = transmissivity

A. both the fluids at inlet (of heat ex¬changer where hot fluid enters) are in their coldest state
B. both the fluids at inlet are in their hot¬test state
C. both the fluids .at exit are in their hottest state
D. one fluid is in hottest state and other in coldest state at inlet
E. any combination is possible depending on design of heat exchanger

A. moisture
B. density
C. temperature
D. all of the above
E. none of the above

A. temperature
B. thickness
C. area
D. time
E. area and time

A. quantity of heat flowing in one second through one cm cube of material when opposite faces ^re maintained at a temperature difference of 1°C
B. quantity of heat flowing in one second through a slab of the material of area one cm square, thickness 1 cm when its faces differ in temperature by 1°C
C. heat conducted in unit time across unit area through unit thickness when a temperature difference of unity is maintained between opposite faces
D. all of the above
E. none of the above

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

where a = absorptivity, p = reflectivity, X = transmissivity

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. 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

A. its temperature
B. nature of the body
C. kind and extent of its surface
D. all of the above
E. none of the above