Available Answers

1. 1.

   Choose the most appropriate answer.

   1. Heat energy causes a sensation of
      1. warmth.
      2. coldness.
      3. both warmth and coldness.
      4. none of these
   2. Which thermometric scale is not divided into 100 units between upper and lower fixed points?
      1. Celcius scale
      2. Fahrenheit scale
      3. Kelvin scale
      4. None of these
   3. Which of these is a good conductor of heat?
      1. Water
      2. Mercury
      3. Wool
      4. Air
   4. The fastest mode of heat transfer is
      1. convection.
      2. radiation.
      3. conduction.
      4. none of these
   5. The mode of transfer of heat in which the particles of the medium actually move is called
      1. convection.
      2. radiation.
      3. conduction.
      4. none of these
   6. Ventilators are made on top of walls in a room because
      1. warm air sinks downwards.
      2. warm air rises upwards.
      3. cold air rises upwards.
      4. none of these
   7. During night time, air blows
      1. from land to sea.
      2. from sea to land.
      3. from sea shore towards the sea.
      4. none of these
   8. Black surfaces are
      1. only good absorbers of heat.
      2. only good radiators of heat.
      3. good absorbers and good radiators of heat.
      4. bad absorbers and good radiators of heat.
   9. Which of the following is an effect of heat?
      1. change in temperature
      2. change in size
      3. change in state
      4. all of these
   10. Walls of houses in hot regions are painted white so that the houses
       1. stay warm during summer.
       2. stay cool during summer.
       3. stay warm during winter.
       4. stay cool during winter.
2. 2.

   Fill in the blanks.

   1. Heat cannot be transferred by convection in __________________.
   2. When heated, liquids and gases have __________________ expansion.
   3. The double walls of a thermos flask reduce loss of heat due to _________________ and _______________________.
   4. The fusion point of ice is _________________ °C.
   5. ___________________ and _________________ are two examples of sublimates.
   6. A bimetallic strip used in a fire alarm is made of ________________ and _______________.
3. 3.

   Define Melting point.

4. 4.

   Define Freezing point.

5. 5.

   Define Boiling point.

6. 6.

   Define Condensation point.