Ans: (b)
193. Petroleum ether is also known as
(a) kerosene
(b) naphtha
(c) lubricating oil
(d) asphalt
Ans: (b)
194. Which one of the following is used for dry cleaning?
(a) Kerosene oil
(b) Diesel oil
(c) Lubricating oil
(d) Petroleum ether
Ans: (d)
195. Which of the following is used as an illuminant?
(a) Gasoline
(b) Benzoline
(c) Kerosene
(d) Petroleum ether
Ans: (c)
196. The alloy which is extremely hard and resistant to acids is
(a) chrome steel
(b) silicon steel
(c) stainless steel
(d) invar
Ans: (b)
197. The process of heating steel to bright red heat and cooling suddenly by plunging it into water is known as
(a) annealing
(b) hardening
(c) quenching
(d) tempering
Ans: (b)
198. Rusting of iron cannot be prevented by
(a) painting
(b) applying alkaline phosphate
(c) applying soap water
(d) galvanising
Ans: (c)
199. The percentage of silver in German silver is
(a) ten
(b) twenty
(c) zero
(d) fifty
Ans: (c)
200. Which of the following is a communicable disease caused by viruses?
(a) Cholera
(b) Dysentery
(c) Diabetes
(d) Measles
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