Top 1000+ Solved Heat Transfer (HT) MCQ Questions Answer
Q. A body cools from 80?C to 70?C in 10 minutes. The time taken by the body for further cooling to 60?C will be
a. 5 minutes
b. 7 minutes
c. 10 minutes
d. More than 10 minutes
e. Less than 10 minutes
Q. Calorific value of Indian coal is
a. 5700 kcal/kg
b. 9600 kcal/kg
c. Nichrome
d. 3300 kcal/kg
e. 2000 kcal/kg
Q. The statement that the emissivity and absorptivity of a surface is surrounded by its own temperature are the same for both monochromatic and total radiation, is known as
a. Kirchhoff's law
b. Lambert law
c. Stefan Boltzman low
d. D'Alembert's rule
e. Law of emissivity
Q. Emissivity and absorptivity of a surface are equal for radiation
a. 37,500 kg
b. in ultraviolet region
c. in radio frequency range
d. with equal temperature and wavelength
e. infrared region
Q. The equation ?m x T = constant represents
a. Wein's Law
b. Kirchhoff's law
c. Stefan Boltzmann's law
d. None of the above
e. Nichrome
Q. The face temperatures of a flat wall are 650?C and 450?C respectively and the thermal conductivity of wall material is 0.30 kcal/m-hr-?C. For a wall thickness of 20 cm, the rate of heat conduction per square meter of wall area will be
a. 37,500 kg
b. 300 kcal/hr
c. 600 kcal/hr
d. 3000 kcal/hr
e. 150 kcal/hr
Q. Pipes are insulated so that
a. There is minimum corrosion
b. Heat loss from the surface is minimized
c. They can withstand higher fluid pressures
d. Vibrations resulting from fluid flow are minimized
e. They may not break under pressure
Q. The value of Stefan Boltzmann's constant in kcal-m2-hr-k4 is
a. 0.174 x 10-8
b. 0.567 x 10-4
c. 4.87 x 10-8
d. 56.7 x 10-9
e. 1.335 x 10-12
Q. An isotherm is a graph
a. Showing pressure volume changes at constant temperature
b. Connecting points of equal pressure
c. Constant temperature
d. Connecting points of equal temperature
e. Showing product of pressure and volume against pressure
Q. A non-dimensional number which generally finds application in mass transfer problems is
a. Stanton number
b. Weber number
c. Grashoff number
d. Mach number
e. Graetz number
Q. The mass of water vapour per kg of the pressure of saturated vapour at the air is known as
a. Specific humidity
b. Relative humidity
c. Molar humidity
d. Humidity ratio
e. None of the above
Q. Unsaturated vapours
a. Do not obey gas laws
b. Obey Boyle's law and not Boyles law
c. Fully obey gas laws
d. Superheated vapour
e. Partly obey gas laws depending upon the degree of unsaturation
Q. Kinematic viscosity indicates
a. heat energy transport through conduction
b. 37,500 kg
c. heat evergy transport through convection
d. conversion of momentum into heat energy
e. momentum transport by molecular friction
Q. A piece of metal with a circular hole is heated. If the metal expands on heating the diameter of the hole will
a. Increase
b. Decrease
c. Increase or decrease depending upon the diameter of the whole
d. Increase or decrease depending on the kind of the metal
e. None of the above