(a)  absorption of other colours by water molecules
       (b)  reflection of the blue light by the impurities in sea water
       (c)  reflection of blue sky by sea water and scattering of blue light by water molecules
       (d)  None of the above
Ans : (c)
128. A lighted candle gets extinguished when covered with a tumbler because of: [I. Tax & Central Excise 1989]
       (a) adequate supply of air
       (b) inadequate supply of air
       (c) presence of non-luminous matter
       (d) None of the above
Ans : (b)
129. A weather balloon is not fully inflated on the ground because:
       (a) it cannot rise up in the air when fully inflated
       (b) it cannot withstand the outside pressure if fully inflated
       (c) if the balloon is fully inflated, it may not remain stable in a storm
       (d) the air inside the balloon expands as it rises and may burst
Ans : (d)
130. One should not connect a number of electric appliances to the same power socket because:
       (a) the appliances will not get full voltage
       (b) the appliances wilt not get proper current
       (c) this can damage the appliances
       (d) this can damage the domestic wiring due to overheating
Ans : (d)
131. Small drops. of a liquid are spherical in shape because: [NDA 1993]
       (a) the earth attracts all the particles of the drop equally
       (b) for a given volume, the surface area of a sphere is maximum
       (c) the surface energy is maximum for the spherical shape
       (d) the surface energy is minimum for the spherical shape
Ans : (d)
132. A ship rises as it enters the sea from a river because the: [CBI 1990]
       (a) water in sea is hard
       (b) larger quantity of water in the sea pushes the ship upwards
       (c) density of sea water is lower than that of the river water
       (d) density of sea water is higher than that of the river water
Ans : (d)
133. The stars twinkle in the night because: [BSF 1989]
       (a) they emit light intermittently
       (b) the star"s atmosphere absorbs light intermittently
       (c) the earth"s atmosphere absorbs light intermittently
       (d) the refractive index of the air in atmosphere fluctuates
Ans : (d)
134. Why are two blankets warmer than one? [Intelligence Bureau 1994]
       (a) Two blankets have more wool and hence, provide greater warmth
       (b) Two blankets enclose air which does not allow the cold to penetrate