Remove condensate from the steam pipelines
Create vacuum
Superheat the steam
None of these
✅ The correct answer is option B.
Engineering MCQs
The left face of a one dimensional slab of thickness 0.2 m is maintained at 80°C and the right face is exposed to air at 30°C. The thermal conductivity of the slab is 1.2 W/m.K and the heat transfer co-efficient from the right face is 10 W/m².K. At steady state, the temperature of the right face in °C is
77.2
71.2
63.8
48.7
✅ The correct answer is option D.
In the free convection regime of pool boiling, the heat flux is proportional to
Δt1/2
Δt2
Δt5/4
Δt
✅ The correct answer is option C.
What is the emissivity of a black body?
1
0
0.9
0.5
✅ The correct answer is option A.
Mode of heat transfer in which the fluid moves under the influence of changes in fluid pressure produced by external work is called
Radiation
Natural convection
Forced convection
Conduction
✅ The correct answer is option C.
What is the steam economy in case of a single effect evaporator system?
1
>1
< 1
0.1
✅ The correct answer is option C.
Fourier’s law of heat conduction applies to __________ surfaces.
Isothermal
Non-isothermal
Both A and B
Neither A and B
✅ The correct answer is option C.
In case of heat transfer by conduction in a hollow cylinder, __________ mean area is used to calculate the heat transfer rate.
Geometric
Arithmetic
Logarithmic
Either A, B or C
✅ The correct answer is option C.
In case of a multipass shell and tube heat exchanger, providing a baffle on the shell side __________ the heat transfer rate.
Increases
Decreases
Does not affect
May increase or decrease, depends on the type of baffle
✅ The correct answer is option A.
A composite wall consists of two plates A and B placed in series normal to the flow of heat. The thermal conductivities are kA and kB and the specific heat capacities are CPA and CPB for plates A and B respectively. Plate B has twice the thickness of plate A. At steady state, the temperature difference across plate A is greater than that across plate B, when
CPA > CPB
CPA < CPB
KA < 0.5kB
KA>2 kB
✅ The correct answer is option C.