6. Which physical quantity is measured in watts
   (a) power
   (b) kinetic energy
   (c) momentum
   (d) impulse
Ans: (a)
7. The theory that the earth constituted the centre of the universe around which
   the sun and the planets revolved was propounded by
   (a) Copernicus
   (b) Ptolemy
   (c) Newton
   (d) Kepler
Ans: (b)
8. It is more difficult to walk on ice than on a concrete road because
   (a) there is very little friction between the ice and feet pressing it
   (b) ice is soft when compared to concrete
   (c) there is more friction between the ice and feet
   (d) None of the above
Ans: (a)
9. When the velocity of a body is halved
   (a) its momentum is halved
   (b) its kinetic energy is halved
   (c) its acceleration is halved
   (d) its potential energy is halved
Ans: (a)
10.The inability of a body to change its state of rest or uniform motion along a
   straight line is called its
   (a) momentum
   (b) velocity
   (c) acceleration
   (d) inertia
Ans: (d)