Engineering :: Heat Transfer

@ : Home > Mechanical Engineering > Heat Transfer

251.

The ratio of thermal conductivity of water to that of ice is nearly

252.

Which of the following material has thermal conductivity closest to silver?

A.	Copper	B.	Brass
C.	Aluminium	D.	Steel

253.

The ratio of thermal conductivity of copper to that of brass is nearly

A.	8	B.	4
C.	2

254.

If thermal conductivity of aluminium is say 100 units at 0?C, the thermal conductivity at 500?C will be closer to

A.	20 units	B.	50 units
C.	100 units	D.	140 units

255.

The value of reheat factor is of the order of

A.	Less than 1	B.	1.02 to 1.06
C.	1.2 to 1.6	D.	More than 2

256.

In case of ideal mono-atomic gas, the ratio of specific heats would be

257.

Which of the following has the highest value of the thermal conductivity

258.

Calorific value of Indian coal is

A.	2000 kcal/kg	B.	3300 kcal/kg
C.	5700 kcal/kg	D.	9600 kcal/kg

259.

A steam pipe is to be insulated by two insulating materials put over each other. For best results

A.	Better matt. Over pipe and inferior over it	B.	Inferior matt. Over pipe and better over it
C.	Can be in any order	D.	None of the above

260.

The average value of thermal conductivity for air at 20?C is about

A.	0.11	B.	0.011
C.	0.022	D.	None of the above