300. Which of the toxic heavy metals is found in modern tannery industries? [CPO SI 2011]
(a) Nickel
(b) Zinc
(c) Chromium
(d) Lead
Ans: (c)
301. Which of the following contains high content of lead? [CPO SI 2011]
(a) Coal
(b) Cooking gas
(c) High octane fuel
(d) Low octane fuel
Ans: (c)
302. Cooking gas is a mixture of [CPO SI 2010]
(a) methane and ethylene
(b) carbon dioxide and oxygen
(c) butane and propane
(d) carbon monoxide and carbon dioxide
Ans: (c)
303. Two elements which are used to absorb neutrons to control the chain reaction during nuclear fission are [CPO SI 2010]
(a) Boron and Cadmium
(b) Boron and Plutonium
(c) Cadmium and Uranium
(d) Uranium and Boron
Ans: (a)
304. The most commonly used chemicals in the artificial rain making or cloud seeding are [CPO SI 2010]
(a) Silver Iodide (Agl)
(b) Sodium Chloride (NaCl)
(c) Dry Ice (Frozen CO2)
(d) All of the above
Ans: (a)
305. Consider the following:
1) Carbon dioxide
2) Oxides of Nitrogen
3) Oxides of Sulphur
Which of the above is/are the emission/emissions from coal combustion at thermal power plants? [CSAT 2011]
(a) 1only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
Ans: (d)
306. Silver ware turns black after a period of time due to formation of: [NDA 2011]
(a) nitrate coating on silver .
(b) sulphide coating on silver
(c) chloride coating on silver
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