Thermal conductivity of solid metals with rise in temperature normally___________________?

A. Increases
B. Decreases
C. Remains constant
D. May increase or decrease depending on temperature

Sensible heat is the heat required to __________________?

A. Change vapour into liquid
B. Change liquid into vapour
C. Increase the temperature of a liquid of vapour
D. Convert water into steam and superheat it

Unit of thermal conductivity in S.I. units is__________________?

A. j/m2 sec
B. j/m °k sec
C. w/m °k
D. a. and c. above

Heat transfer in liquid and gases takes place by_____________________?

A. Conduction
B. Convection
C. Radiation
D. Conduction and convection

Heat flowing from one side to other depends directly on ___________________?

PicK up the wrong case?


D. None of these

Which of the following is the case of heat transfer by radiation ___________________?

A. Blast furnace
B. Heating of building
C. Cooling of parts in furnace
D. Heat received by a person from fireplace

Which of the following is a case of steady state heat transfer ___________________?

A. i.c. engine
B. air preheaters
C. heating of building in winter
D. all of the above

Thermal conductivity of water in general with rise in temperature ____________________?

A. Increases
B. Decreases
C. Remains constant
D. May increase or decrease depending on temperature

Temperature of steam at around 540°C can be measured by ____________________?

A. Thermometer
B. Radiatiouv pyrometer
C. Thermistor
D. Thermocouple

Metals are good conductors of heat because________________?

A. Their atoms collide frequently
B. Their atoms-are relatively far apart
C. They contain free electrons
D. They have high density