A. 1 :1
B. 2: 1
C. 1 : 2
D. 4 : 1
E. 1 : 4
Related Mcqs:
- When heat is transferred from one particle of hot body to another by actual motion of the heated particles, it is referred to as heat transfer by ___________________?
A. conduction
B. convection
C. radiation
D. conduction and convection
E. convection and radiation - Log mean temperature difference in case of counter flow compared to parallel flow will be________________?
A. same
B. more
C. less
D. depends on other factors
E. none of the above - 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 - Heat is transferred by all three modes of transfer, viz, conduction, convection and radiation in _________________?
A. electric heater
B. steam condenser
C. melting of ice
D. refrigerator condenser coils
E. boiler - Heat transfer by radiation mainly depends upon___________________?
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 - The amount of radiation mainly depends on___________________?
A. nature of body
B. temperature of body
C. type of surface of body
D. all of the above
E. none of the above - The total emissivity power is .defined as the total amount of radiation emitted by a black body per unit_______________?
A. temperature
B. thickness
C. area
D. time
E. area and time - According to Stefan’s law, the total radiation from a black body per second per unit area is proportional to____________________?
A. absolute temperature
B. T2
C. T5
D. t
E. l/T - 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 - Total emissivity of polished silver compared to black body is___________________?
A. same
B. higher
C. more or less same
D. very much lower
E. very much higher
