Engineering :: Heat Transfer

@ : Home > Mechanical Engineering > Heat Transfer

201.

If two systems are being compared on the basis of temperature and heat flux, the similarity being considered is

A.	dynamic similarity	B.	kinematic similarity
C.	thermal similarity	D.	geometrical similarity

202.

Which dimensionless number indicates the relative strength of the buoyant to viscous forces?

A.	Prandtl number	B.	Grashoff number
C.	Froude's number	D.	Weber number

203.

A high value of Prandtl number indicates

A.	rapid diffusion of momentum by viscous action compared to diffusion of energy	B.	relative heat transfer by conduction to convection
C.	rapid heat transfer by forced convection to natural convection	D.	None of the above

204.

Kinematic viscosity indicates

A.	momentum transport by molecular friction	B.	heat energy transport through conduction
C.	heat evergy transport through convection	D.	conversion of momentum into heat energy

205.

Prandtl number for gases is

A.	near unity	B.	between 10 to 100
C.	between 100 and 1000	D.	more than 1000

206.

Prandtl number for liquid metals is generally in the range

A.	1000 to 10,000	B.	100 to 1000
C.	10 to 100	D.	0.003 to 0.01

207.

The ratio of heat transfer coefficient to the flow of heat per unit temperature rise due to the velocity of the fluid is known as

A.	Prandtl number	B.	Grashoff number
C.	Stanton number	D.	Weber number

208.

In which of the following heat exchange process, the value of overall heat transfer coefficient will be highest?

A.	Air to heavy tars	B.	Air to carbondioxide
C.	Steam to oil	D.	Steam condensers

209.

For which fluid combination the value of overall heat transfer coefficient will be least?

A.	Feed water heaters	B.	Alcohol condensers
C.	Air to heavy tars	D.	Air condensers

210.

Ablation heat transfer method is used on

A.	submarines	B.	rockets
C.	satellites	D.	nuclear war heads