Top 1000+ Solved Heat Transfer (HT) MCQ Questions Answer

From 481 to 495 of 836

Q. The thermal conductivity of wood depends upon

a. Density

b. Moisture content

c. Temperature

d. All of the above

e. None of the above

  • d. All of the above

Q. In case of natural covection, the Nusselt number is function of

a. Reynolds number

b. Reynolds number and Prandtl number

c. Grashof's number and Prandtl number

d. Weber number and Mach number

e. None of the above

  • c. Grashof's number and Prandtl number

Q. Transient heat flow occurs in

a. Cooling of casting

b. Heating and cooling of buildings due to sun

c. Electric conductors carrying current

d. Melting of ice

e. Insulated pipes carrying superheated steam

  • b. Heating and cooling of buildings due to sun

Q. If thermal conductivity of aluminium is say 100 units at 0?C, the thermal conductivity at 500?C will be closer to

a. 37,500 kg

b. 100 units

c. 20 units

d. 140 units

e. 50 units

  • d. 140 units

Q. The highest value of thermal conductivity is expected for

a. Solid ice

b. Water

c. Melting ice

d. Steam

e. Boiling water

  • a. Solid ice

Q. If the roof of a house is painted with a shiny metallic paint, the temperature inside will

a. Rise

b. Fall

c. Remain unchanged

d. Depends on other factors

e. None of the above

  • b. Fall

Q. Plank's law of radiation is applicable to

a. Radiation of any kind

b. Temperature radiation

c. Monochromatic radiation

d. Thermal radiation

e. None of the above

  • c. Monochromatic radiation

Q. Diffusion coefficient of water into air at 26?C is nearly

a. 5.2 cm2/s

b. 2.6 cm2/sec

c. 0.026 cm2/s

d. 2.6 cm2/s

e. 0.26 cm2/s

  • e. 0.26 cm2/s

Q. Hydrogen cannot be liquefied at room temperature because

a. it is a diatomic gas

b. its critical temperature is less than the room temperature

c. 37,500 kg

d. it has low density

e. it has high specific heat

  • b. its critical temperature is less than the room temperature

Q. Ablation heat transfer method is used on

a. nuclear war heads

b. submarines

c. 37,500 kg

d. satellites

e. rockets

  • d. satellites

Q. In case of a body transparent to thermal radiation

a. transmissibility = 0

b. 37,500 kg

c. absorptivity = 1

d. reflectivity = 1

e. absorptivity = reflectivity = 0

  • e. absorptivity = reflectivity = 0

Q. The phenomenon of boiling the milk in an open container when milk spills over the vessel is termed as

a. Film boiling

b. Pool boiling

c. Sub-cooled boiling

d. Interface evaporation

e. Nuclear boiling

  • a. Film boiling

Q. A hollow sphere with uniform interior temperature and a small hole behaves very nearly as a

a. White body

b. Transparent body

c. Opaque body

d. Black body

e. Grey body

  • d. Black body
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