3166: Assertion (A) :
Large cold storage plants use ammonia as refrigerant while domestic refrigerators use chlorofluorocarbons.
Reason (R) :
Ammonia can be liquefied at ambient temperatures at low pressures.
(a) Both A and R are true, and R is the correct explanation of A
(b) Both A and R are true, but R is not a correct explanation of A
(c) A is true, but R is false
(d) A is false, but R is true
3167: In the year 2001, in which one of the following events of Women's Singles did Venus Williams defeat Serena Williams to win the title?
(a) Australian Open 2001
(b) French Open 2001
(c) Wimbledon 2001
(d) US Open 2001
3168: Among the reasons for disguised unemployment in rural areas is
(a) Choice of a heavy industry model for economic development
(b) Low levels of technological development in the country
(c) Heavy pressure of population along with half-hearted implementation of agrarian reforms
(d) High illiteracy rates
3169: Qantas Airways belongs to:
(a) Australia
(b) West Germany
(c) East Germany
(d) New Zealand
3170: Consider the following statements :
In a nuclear reactor, self-sustained chain reaction is possible, because
I. more neutrons are released in each of the fission reactions.
II. the neutrons immediately take part in the fission process.
III. the fast neutrons are slowed down by Graphite.
IV. every neutron realeased in the fission reaction initiates further fission.
Which of these statements are correct ?
(a) I, II and III
(b) I and III
(c) II and IV
(d) II, III and IV