441. With increase in temperature, the thermal conductivity of most liquids
Increases
Decreases
Remains same
First increases upto a certain temperature and then becomes constant
✅ The correct answer is option B.
Heat Transfer MCQs
442. A concentric double pipe heat exchanger as compared to the shell and tube heat exchanger for the same heat load requires
Less heating surface
More space
Lower maintenance cost
None of these
✅ The correct answer is option B.
443. Heat flux through several resistances in series in analogous to the current flowing through several
Resistances in parallel
Capacitors in series
Resistances in series
None of these
✅ The correct answer is option C.
444. A body is called grey if the monochromatic emissivity of the body is
Zero
Unity
Same for all wavelengths
Different for all wavelengths
✅ The correct answer is option C.
445. An ejector is used to
Increase pressure
Increase temperature
Remove condensate
None of these
✅ The correct answer is option D.
446. Grashoff number, which is defined as g . β(Ts – T∞) ρ². L³/μ², is proportional to the ratio of buoyancy force to __________ force.
Viscous
Elastic
Inertial
None of these
✅ The correct answer is option A.
447. In a boiling curve, the peak heat flux is called the __________ point.
Nusselt
Leidenfrost
Boiling
Burnout
✅ The correct answer is option D.
448. Heat transfer rate described by Fourier’s law will decrease, if the __________ increases.
Thermal conductivity
Thickness
Temperature difference
Heat transfer area
✅ The correct answer is option B.
449. Boiling point elevation of an ideal solution
Increases rapidly with temperature rise
Decreases rapidly with temperature rise
In independent of pressure
Both B and C
✅ The correct answer is option A.
450. With increase in the distance between the heat source and the object receiving the heat, the radiation heat transfer
Decreases
Increases
Increases exponentially
Remains unaffected
✅ The correct answer is option A.