1662. Critical value of the __________ number governs the transition from laminar to turbulent flow in free convection heat transfer.
Grashoff
Reynolds
Both A & B
Prandtl & Grashoff
✅ The correct answer is option D.
1664. Kg of liquid evaporated per hour in an evaporator is defined as its
Capacity
Economy
Steam load
None of these
✅ The correct answer is option A.
1666. Nusselt number is a function of Prandtl number and __________ number of fluid in natural convection heat transfer.
Grashoff
Biot
Stantan
Reynolds
✅ The correct answer is option A.
1672. Fluid motion in the natural convection heat transfer between a solid surface and a fluid in contact with it, results from the
Existence of thermal boundary layer
Temperature gradient produced due to density difference
Buoyancy of the bubbles produced at active nucleation site
None of these
✅ The correct answer is option D.
1675. Prandtl and Reynold’s analogies are identical for Prandtl number value of
0
0.5
1
5
✅ The correct answer is option C.
1639. Which has the lowest Prandtl number?
Liquid metal
Aqueous solution
Water
Lube oil
✅ The correct answer is option A.
1642. It is not preferable to use superheated steam in evaporators, because of its very
High temperature
High pressure
Low film co-efficient
None of these
✅ The correct answer is option C.
1645. __________ chart is known as transient heat conduction chart.
Dirhing’s
Heisler’s
Mollier’s
Cox
✅ The correct answer is option A.
1648. The statement that “maximum wavelength of radiation is inversly proportional to the temperature” is __________ law.
Stefan-Boltzman’s
Planck’s
Wien’s displacement
None of these
✅ The correct answer is option C.