432. Separating particles from a suspension is effected by
(a) centrifugal force
(b) frictional force
(c) gravitational force
433. Which metal is used in storage batteries?
434. Rain drops acquire spherical shape due to
(b) surface tension
435. The spectrum of white light can be studied by
(a) a microscope
(b) a telescope
(c) a stereoscope
(d) a spectroscope
436. A small bubble of air deep down in a lake rises up to the top of the lake.
The volume of the bubble on coming up will
(c) will not change
(d) first increase and then decrease