225. Which of the following statements is wrong about sound ?
(a) Sound can travel in water
(b) Sound is invisible
(c) Sound can be measured
(d) Sound travels faster in vacuum than in air
226. When the velocity is halved, the kinetic energy of a body will
(a) Become one fourth of the original
(b) Become one half of the original
(c) Be doubled
(d) Remain the same
227. Sodium hydroxide produced when 2.3g of sodium metal reacts with water is
(a) 8g
(b) 6g
(c) 4g
(d) 2g
229. The major constituent of atmosphere is
(a) Oxygen
(b) Cabon dioxide
(c) Nitrogen
(d) Water vapour
230. The major raw material for ceramic industries is
(a) Gypsum
(b) Limestone
(c) Kaolin
(d) Quartz
231. The important feature of a neutron bomb is that when it is dropped on a city it would damage the
(a) Living organisms but spare buildings
(b) Buildings but spare the living beings
(c) Animals but spare human beings
(d) Living beings as well as buildings
232. Condensation in the atmosphere occurs when the
(a) Absolute humidity is high
(b) Temperature reaches the dew point
(c) Relative humidity exceeds 75%
(d) Temperature drops below the freezing point
233. The experiment which is the best proof of the earth’s rotation is the
(a) Kepler’s experiment of motion
(b) Newton’s experiment of gravity
(c) Galileo’s experiment of motion
(d) Foucault’s experiment of pendulum
234. Plants stop taking carbon dioxide during
(a) Night-time
(b) Twilight
(c) Day-time
(d) Dawn
235. Mercury is used in barometer because
(a) It has high specific gravity
(b) It doesn’t stick to the walls of the glass
(c) It is a shining liquid
(d) All of the above
236. Non-functioning of kidney is due to
(a) High blood pressure
(b) Accumulation of nitrogenous wastes
(c) Low blood pressure
(d) Presence of water in blood
237. Percentage of water in the human body is approximately
(a) 65%
(b) 25%
(c) 35%
(d) 45%