The heat transfer by radiation from a mild steel surface is...

Home / Chemical Engineering / Heat Transfer / Question

Examveda

The heat transfer by radiation from a mild steel surface is to be reduced by reducing the emissivity of the surface. This can be best achieved by

A. Painting the surface black

B. Painting the surface white (with aluminium paint)

C. Giving the surface a mirror finish

D. Roughening the surface

Answer: Option B

This Question Belongs to Chemical Engineering >> Heat Transfer

Join The Discussion

Related Questions on Heat Transfer

200 kg of solids (on dry basis) is subjected to a drying process for a period of 5000 seconds. The drying occurs in the constant rate period with the drying rate as, N_c = 0.5 × 10^-3 kg/m².s. The initial moisture content of the solid is 0.2 kg moisture/kg dry solid. The interfacial area available for drying is 4 m²/1000 kg of dry solid. The moisture content at the end of the drying period is (in kg moisture/kg dry solid)

A. 0.5

B. 0.05

C. 0.1

D. 0.15

View Answer

It is desired to concentrate a 20% salt solution (20 kg of salt in 100 kg of solution) to a 30% salt solution in an evaporator. Consider a feed of 300 kg/min at 30°C. The boiling point of the solution is 110°C, the latent heat of vaporisation is 2100 kJ/kg and the specific heat of the solution is 4 kJ/(kgK). The rate at which the heat has to be supplied in (kJ/min) to the evaporator is

A. 3.06 × 10⁵

B. 6.12 × 10⁵

C. 7.24 × 10⁵

D. 9.08 × 10⁵

View Answer

Fqra cold viscous feed, backward feed gives __________ than forward feed.

A. A higher capacity

B. A lower capacity

C. Lower economy

D. None of these

View Answer

In a multipass shell and tube heat exchanger, tube side return pressure loss is equal to __________ the velocity head.

A. Twice

B. Four times

C. Square root of

D. Square of

View Answer

More Related Questions on Heat Transfer