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151.

Which rays have the least wavelength?

152.

Which of the following property of air does not increase with rise in temperature?

153.

The emissive power of a body depends on

154.

The emissivity of a body will be equal to absorptivity when

A.	Body is at low temperature	B.	Body is at high temperature
C.	Temperature of body is rising	D.	Temperature of body is falling
E.	Body is in thermal equilibrium

155.

The wavelength for maximum emissive power is given by

156.

If the bubbles formed on a submerged hot surface get absorbed in the mass of liquid, the process of boiling is termed as

157.

In case the hydrodynamic and thermal boundary layers are identical for a fluid flowing over a heated plate

A.	The plate must be of low thermal conductivity	B.	The plate surface must be smooth
C.	The value of Prandtl number thust be 1	D.	The value of Prandtl number must be zero
E.	The value of Prandtl number must be 0.5

158.

In case of natural covection, the Nusselt number is function of

A.	Reynolds number	B.	Reynolds number and Prandtl number
C.	Grashof's number and Prandtl number	D.	Weber number and Mach number
E.	None of the above

159.

Fouling factor

A.	Is dimensionless	B.	Measures the heat transfer efficiency
C.	Is virtually a factor of safety in heat exchanger design	D.	Is used when a liquid exchanges heat with a gas
E.	Is used only in case of Newtonian fluids

160.

Heat sensitive liquids are connected

A.	By using insulated vessels	B.	By using small quantities
C.	By using deoxidisers	D.	By using vacuum
E.	By using low intensity heating