(11) A boat gets most easily rocked if it is
(a) Broad and heavy
(b) Narrow and heavy
(c) Narrow and light
(d) Broad and light
(12) Powder clings to the skin because of
(a) Absorption
(b) Cohesion
(c) capillary action
(d) Adhesion
(13) A device used to measure heights above sea level is known as
(a) Anemometer
(b) Dilatometer
(c) Potentiometer
(d) Altimeter
(14) Sound travels fastest in
(a) iron
(b) water
(c) air
(d) vacuum
(15) Out of the following which is the non-magnetic substance
(a) Cobalt
(b) Iron
(c) Copper
(d) Nickel
(16) Lines of force due to earth’s horizontal magnetic field are
(a) Concentric circles
(b) Curved Lines
(c) Straight and Parallel
(d) Elliptical
(17) For a given frequency the loudness is related to
(a) Speed
(b) Amplitude
(c) Wavelength
(d) None of the above
(18) One can be recognized by one’s voice alone due to voice’s factor of
(a) Quality
(b) Pitch
(c) Amplitude
(d) Loudness
(19) Under similar conditions of temperature and pressure, the velocity of sound is maximum in
(a) Helium
(b) Oxygen
(c) Argon
(d) Hydrogen
(20) Darwin’s theory of nature selection involves :
(a) Competition
(b) Over reproduction
(c) Survival of the fittest
(d) All of these