Chemical Engineering Mcqs

A hot liquid is kept in a big room. The logarithm of the numerical value of the temperature difference between the liquid and the room is plotted against time. The plot will be very nearly a/an___________________?

• (A)  Ellipse
• (B)  Straight line
• (C)  Parabola
• (D)  Circular arc

Answer

Submitted By :Ali Uppal

A hot body will radiate heat most rapidly, if its surface is___________________?

• (A)  White & rough
• (B)  Black & rough
• (C)  White & polished
• (D)  Black & polished

Answer

Submitted By :Ali Uppal

Prandtl number is the ratio of________________?

• (A)  Mass diffusivity to thermal diffusivity
• (B)  Momentum diffusivity to thermal diffusivity
• (C)  Thermal diffusivity to mass diffusivity
• (D)  Thermal diffusivity to momentum diffusivity

Answer

Submitted By :Ali Uppal

Rate of heat transfer by vaporisation from pools of water is affected by the ____________________?

• (A)  Nature of heating surface and distribution of bubbles
• (B)  Surface tension of water
• (C)  Viscosity of water
• (D)  All

Answer

Submitted By :Ali Uppal

The purpose of providing bleed points in the evaporator is to__________________?

• (A)  Admit the feed
• (B)  Remove the product
• (C)  Facilitate removal of non-condensable gases
• (D)  Create vacuum

Answer

Submitted By :Ali Uppal

With increase in temperature, the thermal conductivity of steel___________________?

• (A)  Increases
• (B)  Decreases
• (C)  Remains unchanged
• (D)  Increases exponentially

Answer

Submitted By :Ali Uppal

In a shell and tube heat exchanger, the tube side heat transfer co-efficient just at the entrance of the tube is_________________?

• (A)  Infinity
• (B)  Zero
• (C)  Same as average heat transfer co-efficient for tube side
• (D)  None of these

Answer

Submitted By :Ali Uppal

Which of the following is the most controlling factor for the rate of bubble detachment from the hot solid surface ?

• (A)  Liquid density
• (B)  Liquid viscosity
• (C)  Hot surface temperature
• (D)  Interfacial tension

Answer

Submitted By :Ali Uppal

The energy radiated from a surface Q at absolute temperature T is related as__________________?

• (A)  Q ∝ T2
• (B)  Q ∝ T4
• (C)  Q ∝ T3
• (D)  None of these

Answer

Submitted By :Ali Uppal

Absorptivity of a perfect black body is unity. Which of the following has maximum absorptivity ?

• (A)  Aluminium foil
• (B)  Refractory bricks
• (C)  Iron plate
• (D)  Coke breeze

Answer

Submitted By :Ali Uppal