Heat Transfer MCQ Questions & Answers | Chemical Engineering

A. $${\text{St}} = \frac{{\text{f}}}{2}$$

B. $${\text{St}} = \frac{{\text{f}}}{4}$$

C. St = 4f

D. $${\text{St}} = {{\text{f}}^{\frac{1}{2}}}$$

A. Agitated film evaporator

B. Long tube vertical evaporator

C. Open pan evaporator

D. None of these

A. In process heat exchangers, saturated steam is preferred over the superheated steam

B. The maximum is the emissive power of a surface at a temperature T₁ occurs at a wavelength of λ₁. If the surface temperature is halved, the maximum in the emissive power would occur at a wavelength of 0.5 λ₁

C. When a vertical plate is heated in infinite air environmental under natural convection conditions, the velocity profile in air, normal to the plate, exhibits a maximum

D. A body at 925 K emits an energy of 1.42 × 10¹¹σW/m² (σ is the Stefan-Boltzman constant) in the wavelength band between 3 μm to 4 μm. The fraction of this energy in the total energy emitted over the entire wavelength range is equal to emissivity

A. Boiling point (at the same pressure)

B. Viscosity

C. Density

D. Thermal conductivity

A. Thin walled having the value of A_o A_i/< 2

B. Thick walled

C. Having the value of A_o/A_i > 2

D. Both B and C

A. Heat transfer co-efficient

B. Thermal diffusivity

C. Thermal conductivity

D. Stefan-Boltzman constant

A. Logarithmic mean area

B. Arithmetic mean area

C. Geometric mean area

D. None of these

A. U-tube

B. Double pipe

C. Fixed tube

D. Floating head

A. High pressure

B. Vacuum

C. Backward feed

D. None of these

A. Create vacuum

B. Regulate the vapor flow

C. Vent the non-condensible gases

D. Arrest the entrained liquid