(a) is proportional to its original length
   (b) is proportional to the increase of temperature
   (c) is inversely proportional to its original length
   (d) Both (a) and (b) above
Ans: (d)
109. A thermostat is a device used
   (a) for automatically maintaining a steady temperature
   (b) for measuring electricity
   (c) to reduce the voltage of electricity
   (d) for producing heat
Ans: (a)
110. Heat is transmitted from one end of a metal rod to its other end by the
   method of
   (a) conduction
   (b) convection
   (c) radiation
   (d) sublimation
Ans: (a)
111. In an oil lamp, holes are provided below the chimney so that
   (a) necessary oxygen for burning of oil may be provided
   (b) the convection current of air may be maintained to keep the lamp burning
   (c) the brightness of the lamp may be increased
   (d) All the above
Ans: (d)
112. Thick brick walls are used in the construction or a cold storage because
   (a) are good conductors of heat
   (b) are cheaper
   (c) are easily obtained
   (d) are bad conductors of heat
Ans: (d)