Physics Objective Test No.9


   Multiple Choice Questions
1. When swims across a flowing river, maximum energy is spent in
a) First 1/3 of the distance 
b) Second 1/3 of the distance
c) Last 1/3 of the distance 
d) Equal energy is spent throughout
2. The maximum static friction is
a) Equal to the dynamic friction 
b) Always less than the dynamic friction
c) Always greater than the dynamic friction 
d) Sometimes greater and sometimes equal to dynamic friction
3. If the normal force is doubled, the coefficient of friction is
a) Not changed 
b) Halved
c) Doubled 
d) Tripled
4. The maximum static frictional force is
a) Equal to twice the area of the surface in contact
b) Independent of the area of surface in contact
c) Equal to the area of surface in contact 
d) None of the above
5. Which of the following statements is not true
a) The coefficient of friction between two surfaces will increase if the surface are made rough
b) When a body slides on a surface the force of friction acts opposite to the direction of applied force
c) Rolling friction is more than sliding friction
d) The coefficient of friction between wood and wood is less than 1
6. Maximum value of static friction is called
a) Limiting friction 
b) Rolling friction
c) Normal friction 
d) Coefficient of friction
7. The limiting friction between two bodies in contact is independent of
a) Nature of the surfaces in contact 
b) The area of surfaces in contact
c) Normal reaction between the surfaces 
d) The materials of the bodies
8. The constant ratio which the limiting friction bears with the normal reaction is called
a) Angle of friction 
b) Cone of friction
c) Coefficient of friction 
d) None of the above
9. Friction can be reduced by
a) Providing lubricants 
b) Ball bearings
c) Roller bearings 
d) Any of the above
10. The frictional force which comes into play after the motion has commenced is called
a) Static friction 
b) Dynamic friction
c) Limiting friction 
d) None of the above
Answer