142. Increase in pressure
   (a) increases the melting point of ice
   (b) decreases the melting point of ice
   (c) has no effect on the melting point of ice
   (d) increases the volume of the ice
Ans: (b)
143. Two tumblers stuck together can be separated by
   (a) pouring ice cold water into the inner tumbler
   (b) pouring ice cold water on the outer tumbler
   (c) pouring hot water into the inner tumbler
   (d) dipping both the tumblers in hot water
Ans: (a)
144. Skating on ice is possible because
   (a) the surface of ice is smooth
   (b) ice is cold
   (c) the pressure on the ice due to skate melts the ice by lowering its melting
       point forming a thin film of water
   (d) the pressure on the ice due to skate raises its melting point
Ans: (c)
145. Of the following types of electromagnetic radiation which has the longest
   wavelength?
   (a) ultraviolet rays
   (b) gamma rays
   (c) radio waves
   (d) infrared waves
Ans: (c)
146. Of the following which has got the highest frequency?
   (a) ultraviolet rays
   (b) gamma rays
   (c) radio waves
   (d) infrared waves
Ans: (b)
                                         77