A rope is wrapped twice around a rough pole with a coefficient of friction ‘A . It is subjected to a force Fj at one end and a gradually increasing force F2 is applied at the other end till the rope just starts slip-ping. At this instant the ratio of F2 to Fi is_____________________?

Related Mcqs:

1. A light rope is loaded with many equal weights at equal horizontal intervals. The points of suspension on the rope lie on a_____________________?

   A. parabola
   B. catenary
   C. cycloid
   D. ellipse

2. A ladder of weight ‘w’ rests against a smooth vertical wall, and rests on rough horizontal ground, the coefficient of friction between the ladder and the ground being 1/4. The maximum angle of inclination of the ladder to the vertical, if a man of weight ‘w’ is to walk to the top of it safely, is tan’1 x, where x is___________________?

   A. 1/4
   B. 1/3
   C. 3
   D. 4

3. A cylinder will slip on an inclined plane of inclination 0 if the coefficient of static friction between plane and cylinder is_____________________?

   A. less than (1/3) tan 0
   B. less than (2/3) tan 0
   C. less than (1/3) sin 6
   D. less than (2/3) sin 6

4. A ball moving on a smooth horizontal table hits a rough vertical wall, the coefficient of restitution between ball and wall being 1/3. The ball rebounds at the same angle. The fraction of its kinetic energy lost is___________________?

   A. 1/3
   B. 2/3
   C. 1/9
   D. 8/9

5. Coefficient of friction depends on__________________?

   A. nature of surfaces only
   B. area of contact only
   C. both (A) and (B)
   D. none of the above

6. A force P of 50 N and another force Q of unknown magnitude act at 90° to each other. They are balanced by a force of 130 N. The magnitude of Q is__________________?

   A. 60 N
   B. 80 N
   C. 100 N
   D. 120 N

7. At the instantaneous center, the velocity of the moving lamina at any instant is_________________?

   A. zero
   B. maximum
   C. minimum
   D. varying

8. The pole distance is measured in___________________?

   A. distance scale
   B. force scale
   C. mass scale
   D. time scale

9. The ratio of unit of force in gravitational system to that in absolute system is__________________?

   A. 1
   B. g
   C. 1/g
   D. none of the above
   where ‘g’ is acceleration due to gravity

10. A 2 m long ladder rests against a wall and makes an angle of 30° with the horizontal floor. Where will be the instantaneous center of rotation when the ladder starts slipping ?

    1) 1.0 in from the wall
    2) 1.732 m from the wall
    3) 1.0 m above the floor
    4) 1.732 m above the floor
    The correct answer is?

    A. (1) and (3)
    B. (1) and (4)
    C. (2) and (3)
    D. (2) and (4)