HEAT : 1/2 Mark Questions


1/2 Mark Questions

1. Which substance is used as coolent in car radiators ? 

Ans: Water 

 2. What is the specific heat of ice ? 

 Ans: 0.5 cal / gm-oC

 3. Define absolute temperature. 

 Ans: Temperature measured on kelvin scale is called absolute temperature. 

 4. Convert 27oC into Kelvin scale. 

 Ans:Temperature in Kelvin =273 + toC = 273+27 =300 K. 

 5. What is the specific heat of water ? 

 Ans: 1 cal / gm-oC 

 6. What is the S.I. unit of heat ? 

 Ans: Joule 

 7. What is the S.I. unit of temperature ?

 Ans: Kelvin 

 8. What is the specific heat of kerosene ? 

 Ans: 0.5 cal / gm-oC 

 9. The doctor checked the body temperature of a 10th class student and said his body temperature is 310K. What is the body temperature of that boy in Celsius scale ?

 Ans: 310 - 273 = 37oC 

1 Mark Questions

1. Define Heat. Write its units. 

Ans: Heat is a form of energy which flows from a hot body to a cold body. Units : C.G.S system – Calorie (Cal), S.I system – Joule (J ).

 2. Define Temperature. 

Ans: The degree of hotness or coldness is called temperature. Units : S.I system – Kelvin. 

 3. Define “Calorie”. 

 Ans: The amount of heat required to raise the temperature of 1 gram of water by 1oC is called ‘Calorie’. 1 cal = 4.186 J 

 4. What is “Thermal equilibrium” ? 

 Ans: The state of body where it neither receives nor gives out heat energy is called “Thermal equilibrium”. 

5. Define “Specific Heat”. 

Ans: The amount of heat required to raise the temperature of unit mass of the substance by one unit is called “Specific Heat”. Units : S.I System - J/Kg-K , C.G.S System - Cal/gm-oC 

 6. Convert 20oC into Kelvin scale.

 Ans:Temperature in Kelvin =273 + t oC = 273+20 =293 K. 

 7. Define Principle of Method of mixtures. 

Ans: Principle of Method of mixtures: When two or more bodies at different temperatures are brought into thermal contact, then net heat lost by the hot bodies is equal to net heat gained by cold bodies until they attain thermal equilibrium. Net heat lost = Net heat gain