Heat exchanger tubes are never made of_________________?

A. Plain carbon steel
B. Stainless steel
C. Lead
D. Copper

Grashoff number is given by________________?

A. gD3.β.Δtρ2/μ2
B. gD2βΔtρ/μ2
C. gD2βΔtP2μ
D. gD3βΔtP2/μ

Crystal size in a continuous crystalliser depends upon the___________________?

A. Rate of heat transfer
B. Degree of turbulence
C. Degree of super-saturation
D. All A., B. and C

Multipass heat exchangers are used______________________?

A. Because of simplicity of fabrication
B. For low heat load
C. To obtain higher heat transfer co-efficient and shorter tube
D. To reduce the pressure drop

In Biot number, the characteristic length used is the ratio of the _______________ of the solid?

A. Volume to surface area
B. Perimeter to surface area
C. Surface area to volume
D. Surface area to perimeter

Forced circulation evaporators are useful for the concentration of viscous, salting and scale forming liquors. Which of the following is a forced circulation evaporator ?

A. Long vertical evaporator
B. Horizontal tube evaporator
C. Agitated film evaporator
D. Calandria vertical tube evaporator

The overall resistance for heat transfer through a series of flat resistance, is the _____________ of the resistances?

A. Average
B. Geometric mean
C. Product
D. Sum

Heat transfer by conduction in the turbulent core of a fluid flowing through a heated pipe is negligible, if the value of Prandtl number is_______________?

A. 0.2
B. 0.4
C. 0.6
D. 0.8

In a shell and tube heat exchanger, square pitch compared to triangular pitch__________________?

A. Gives a higher shell side pressure drop
B. Gives a lower shell side pressure drop
C. Can pack more surface area into a shell of given diameter
D. None of these

The ratio of total radiating power to the absorptivity of the body depends upon the _____________ as per Kirchoff‟s law?

A. Wavelength of radiation
B. Nature of the body
C. Temperature of the body
D. None of these