(c) cool down the reactor
   (d) stop the nuclear reaction
Ans: (a)
133. What is the difference between a CFL and a LED lamp?
   1) To produce light, a CFL uses mercury vapour and phosphor while an
       LED lamp uses semiconductor material.
   2) The average life span of a CFL is much longer than that of an LED lamp.
   3) A CFL is less energy-efficient as compared to an LED lamp.
   Which of the statements given above is/ are correct? [CSAT (Pre) 2011]
   (a) 1 only
   (b) 2 and 3 only
   (c) 1 and 3 only
   (d) 1,2 and 3
Ans: (d)
134. Examine the following statements:
   1) Waves of low frequency are actually produced through the flute of lesser
   2) Sound through the rocks only transmitted in the form of longitudinal
       elastic waves.
   Which one of the following of the above statements is/ are true:
   (a) Only 1
   (b) Only 2
   (c) 1 and 2 both
   (d) Neither 1 nor 2
Ans: (b)
135. Consider the following statements:
   1) A person with myopia can see distant objects distinctly but cannot= see
       nearby objects clearly.
   2) A person with hypermetropia cannot see distant objects clearly.
   3) A person with presbyopia can see nearby objects without corrective