If the baffle spacing in a shell and tube heat exchanger increases, then the Reynolds number of the shell side fluid_________________?

A. Remains unchanged
B. Increases
C. Increases or decreases depending on number of shell passes
D. Decreases

For concentrating an aqueous solution of a material like anhydrous Na2SO4, whose solubility decreases with rise in temperature, the most suitable evaporator is a _______________ evaporator?

A. High pressure
B. Vacuum
C. Backward feed
D. None of these

Economy of an evaporator is influenced by the_____________________?

A. Steam pressure
B. Feed temperature
C. Number of effect
D. Both B. & C.

In case of a super-cooled solution, which is on the verge of crystallisation, the free energy of the solution as compared to that of the solid is ________________?

A. More
B. Less
C. Same
D. More or less; depends on the nature of solution

The local surface conductance for laminar film condensation on vertical surface is (where, t = film thickness) _________________?

A. ∝ t
B. ∝ 1/t
C. ∝ √t
D. Independent of ‘t’

Overall heat transfer co-efficient of a particular tube is U1. If the same tube with some dirt deposited on either side has coefficient U2, then_________________?

A. U1 = U2
B. U2 > U1
C. U1 > U2
D. U1 = dirt factor – U2

Dittus-Boelter equation cannot be used for molten metals mainly due to its very low_____________________?

A. Prandtl number
B. Grashoff number
C. Thermal conductivity
D. Viscosity

Steam traps are provided in steam carrying pipelines to_________________?

A. Condense steam
B. Release excess steam pressure by bleeding steam
C. Remove condensate and inert gases
D. None of these

In natural convection heat transfer, the correlating parameter is the_______________________?

A. Graetz number
B. Eckert number
C. Grashoff number
D. Bond number

The value of Stefan-Boltzmann constant in SI unit is_________________?

A. 5.6697 × 10-8W/m2.°K4
B. 0.1714 × 10-8W/m2.°K4
C. 5.6697 × 10-8kcal/m2. °K4
D. 0.1714 × 10-8kcal/m2. °K4