(b) uniform retardation of an object
     (c) non-uniform acceleration of an object
     (d) non-uniform retardation of an object
Ans : (b)
299. Which one among the following would expand the most on being heated? [CDS 2011]
     (a) Water
     (b) Alcohol
     (c) Glass
     (d) Air
Ans : (d)
300. A metal plate with a circular hole at the centre is heated. What will happen to the area of the hole? [CPO (SI) 2010]
     (a) Increase
     (b) Decrease
     (c) Remain constant
     (d) Will increase first and then decrease
Ans : (b)
301. Conduction band electrons have more mobility than holes because they - [SSC(10+2) 2010]
     (a) air lighter
     (b) experience collision less frequently
     (c) have negative charge
     (d) need less energy to move them
Ans : (b)
302. The mass number of a nucleus is [SSC(10+2) 2010]
     (a) always less than its atomic number
     (b) always more than its atomic number
     (c) always equal to its atomic number
     (d) sometimes more and sometimes equal to its atomic number
Ans : (d)
303. The pressure exerted on the ground by a man is greatest [CDS 2010]
     (a) when he lies down on the ground
     (b) when he stands on the toes of one foot.
     (c) when he stands with both feet flat on the ground
     (d) all of the above yield the same pressure
Ans : (b)
304. Which of the following is not needed in a nuclear fission reactor? [CDS 2010]
     (a) Moderator
     (b) Coolant
     (c) Accelerator
     (d) Control device
Ans : (c)
305. Magnetism of a bar magnet can be destroyed if it is:
     1) kept in the magnetic meridian.
     2) placed in a direction opposite that of the Earth"s horizontal intensity.
     3) heated to a temperature known as Curie temperature.