Top 1000+ Solved Heat Transfer (HT) MCQ Questions Answer
Q. A sphere 15 cm in diameter is covered with 5 cm of insulation (k = 0.057 kcal/m-hr-?C). The inside and outside surface temperature of the insulation are 315?C and 80?C respectively. The heat loss per sq. m of the outside surface will be closer to
a. 80 kcal/hr
b. 320 kcal/hr
c. 160 kcal/hr
d. 37,500 kg
e. 40 kcal/hr
Q. The net radiant interchange per square metre for two large parallel planes at temperatures of 1000?K and 100?K respectively, would be roughly
a. 240 kcal/hr
b. 75 kcal/hr
c. 25 kcal/hr
d. 480 kcal/hr
e. 120 kcal/hr
Q. Which variety of steel may be expected to have lowest value of thermal conductivity?
a. High carbon steel (0.83% C)
b. Low nickel steel (1.37% Ni)
c. Low chromium steel (0.46% Cr)
d. High chromium steel (0.26% Cr)
e. Chromium nickel steel (9% Ni, 18% Cr)
Q. In an air-conditioning plant a cooling tower is used to cool
a. air
b. refrigerant
c. condenser water
d. None of the above
e. 37,500 kg
Q. Which method can be used for heating wood?
a. Flame heating
b. Resistance heating
c. Dielectric heating
d. Radiation heating
e. Any of the above
Q. A correction of LMTD is necessary in case of
a. Parallel flow heat exchanger
b. Counter current heat exchanger
c. Cross flow heat exchanger
d. All of the above
e. None of the above
Q. The dimensions of thermal conductivity are
a. MLT-3 ?-1
b. MLT?3
c. ML-1T2 ?
d. MLT2 ?2
e. 37,500 kg
Q. In which of the following heat exchange process, the value of overall heat transfer coefficient will be highest?
a. Air to carbondioxide
b. Air to heavy tars
c. 37,500 kg
d. Steam condensers
e. Steam to oil
Q. A thin circulr disc has a concentric hole in it. On heating the diameter of hole will
a. decrease
b. remain constant
c. 37,500 kg
d. increase
Q. Which is the unit of Stefan Boltzmann constant
a. W/m2 K4
b. erg/cm2-sec-K4
c. cal/cm2-sec K4
d. kcal/m2-hr-K4
e. All of the above
Q. According to Wien’s law, the wavelength corresponding to maximum energy isproportion to
a. absolute temperature (T)
b. I2
c. f
d. t
e. 1/r.
Q. Depending on the radiating properties, a body will be white when (where a = absorptivity, p = reflectivity, x = transmissivity)
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.
Q. Depending on the radiating properties, a body will be black when (where a = absorptivity, p == reflectivity, X = transmissivity.)
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 = 0
e. a = 0,x + p= 1.