The insulation ability of an insulator with the presence of moisture would_________________?
(A) increase
(B) decrease
(C) remain unaffected
(D) may increase/decrease depending on temperature and thickness of insulation
(D) none of the above
Heat is closely related with___________________?
(A) liquids
(B) energy
(C) temperature
(D) entropy
(D) enthalpy
Total heat is the heat required to__________________?
(A) change vapour into liquid
(B) change liquid into vapour
(C) increase the temperature of a liquid or vapour
(D) convert water into steam and superheat it
(D) convert saturated steam into dry steam
Thermal conductivity of air with rise in temperature__________________?
(A) increases
(B) decreases
(C) remains constant
(D) may increase or decrease depending on temperature
(D) none of the above
Thermal conductivity of air at room temperature in kcal/m hr °C is of the order of__________________?
(A) 0.002
(B) 0.02
(C) 0.01
(D) 0.1
(D) 0.5
Cork is a good insulator because it has___________________?
(A) free electrons
(B) atoms colliding frequency
(C) low density
(D) porous body
(D) all of the above
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
(D) all of the above
Temperature of steam at around 540°C can be measured by ____________________?
(A) thermometer
(B) radiatiouv pyrometer
(C) thermistor
(D) thermocouple
(D) thermopile
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
(D) none of the above
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
(D) none of the above