Occupies smaller space
Is more economical
Is easy to operate and maintain
All of the above
✅ The correct answer is option D.
Engineering MCQs
The ratio of the total emissive power to the absorptivity for all bodies is same at ther-mal equilibrium. This is __________ law.
Kirchoffs
Planck’s
Wien’s displacement
Stefan-Boltzman
✅ The correct answer is option A.
Reynold’s analogy states that
Nst α f
Nst α NRe
NNu α f
NRe α f
✅ The correct answer is option A.
In the equation Q = UAΔt; Δt is
Geometric mean temperature difference
Arithmetic mean temperature difference
Logarithmic mean temperature difference
The difference of average bulk temperatures of hot and cold fluids
✅ The correct answer is option C.
In case of heat flow by conduction for a cylindrical body with an internal heat source, the nature of temperature distribution is
Linear
Hyperbolic
Parabolic
None of these
✅ The correct answer is option C.
jH factor for heat transfer is not a function of the __________ number.
Reynolds
Nusselt
Grashoff
Both B & C
✅ The correct answer is option D.
In case of a vertical tube evaporator, with increase in the liquor level, the
Capacity of the evaporator is decreased
Capacity of the evaporator is increased
True temperature drop increases
Both B and C
✅ The correct answer is option A.
An insulator should have
Low thermal conductivity
High thermal conductivity
Less resistance to heat flow
A porous structure
✅ The correct answer is option A.
In case of parallel flow heat exchanger, the lowest temperature theoretically attainable by the hot fluid is __________ the outlet temperature of the cold fluid.
Equal to
More than
Less than
Either more or less than (depending upon the fluid)
✅ The correct answer is option A.
Heat transfer co-efficient (h1) for liquids increases with
Increasing temperature
Decreasing temperature
Decreasing Reynolds number
None of these
✅ The correct answer is option A.