Test: Transient Heat Conduction - 1 - Mechanical Engineering MCQ

very little heat transfer

heat transfer for a short time

heat transfer with a very small temperature difference

conduction when the temperature at a point varies with time

the rates of inflow and outflow of mass are different.

the state of matter inside the control volume varies with time.

there can be work and heat interactions across the control volume.

there is no accumulation of energy inside the control volume.

Bi < 0.1

0.1 < Bi < 10

1 < Bi < 10

Bi → ∞

Temperature variations in cycle of an internal combustion engine.

Cooling of bars, blanks and metal billets in steel works.

Variation of temperature of a building during a full day period of 24 hours.

Heat processing of regenerators whose packings are alternately heated by flue gases and cooled by air

1, 3 and 4

1, 2 and 4

2, 3 and 4

All of the above

l = R/3 in case of sphere of radius R.

l = R/2 in case of a cylinder of radius Rand length L.

l = L/6 in case of a cube with each side of length L

l = b/2 for a flat plate of thickness δ, breadth b and height h.

location of point within the solid

Biot number

Prandtl number

Fourier number

parabolic curve asymptotic to time axis

exponential curve asymptotic to time axis

exponential curve asymptotic both to time and temperature axes

hyperbolic curve asymptotic both to time and temperature axes

Fourier number and Reynolds number

Reynolds number and Prandtl number

Biot number and Fourier number

Reynolds number and Biot number

faster in air block

faster in copper block

equal in air as well as copper block

cannot predicted with given information