A semi-circular disc rests on a horizontal surface with its top flat surface horizontal and circular portion touching down. The coefficient of friction between semi-cricular disc and horizontal surface is \i. This disc is to be pulled by a horizontal force applied at one edge and it always remains horizontal. When the disc is about to start moving, its top horizontal force will____________________?

Related Mcqs:

1. A body of weight W on inclined plane of a being pulled up by a horizontal force P will be on the point of motion up the plane when P is equal to________________?

   A. W
   B. W sin (a + $)
   C. Wtan(a + <|))
   D. W\an(a-)
   E. Wtana

2. Friction force for dry surfaces. Friction force is________________?

   Pick up wrong statement?
   A. proportional to normal load between the surfaces
   B. dependent on the materials of contact surface
   C. proportional to velocity of sliding
   D. independent of the area of contact surfaces
   E. none of the above is wrong statement

3. Least force required to draw a body up the inclined plane is W sin (plane inclination + friction angle) applied in the direction___________________?

   A. along the plane
   B. horizontally
   C. vertically
   D. at an angle equal to the angle of friction to the inclined plane
   E. unpredictable

4. Coulomb friction is the friction between _________________?

   A. bodies having relative motion
   B. two dry surfaces
   C. two lubricated surfaces
   D. solids and liquids
   E. electrically charged particles

5. The M.I. of hollow circular section about a central axis perpendicular to section as compared to its M.I. about horizontal axis is__________________?

   A. same
   B. double
   C. half
   D. four times
   E. one fourth

6. Dynamic friction as compared to static friction is___________________?

   A. same
   B. more
   C. less
   D. may be less of more depending on nature of surfaces and velocity
   E. has no correlation

7. From a circular plate of diameter 6 cm is cut out a circle whose diameter is a radius of the plate. Find the e.g. of the remainder from the center of circular plate____________________?

   A. 0.5 cm
   B. 1.0 cm
   C. 1.5 cm
   D. 2.5 cm
   E. 0.25 cm

8. Coefficient of friction is the_________________?

   A. angle between normal reaction and the resultant of normal reaction and the limiting friction
   B. ratio of limiting friction and normal reaction
   C. the friction force acting when the body is just about to move
   D. the friction force acting when the body is in motion
   E. tangent of angle of repose

9. The coefficient of friction depends on________________?

   A. area of contact
   B. shape of surfaces
   C. strength of surfaces
   D. nature of surface
   E. all of the above

10. The resultant of the following three couples 20 kg force, 0.5 m arm, $ ve sense 30 kg force, 1 m arm, – ve sense 40 kg force, 0.25 m arm, + ve sense having arm of 0.5 m will be__________________?

    A. 20 kg, – ve sense
    B. 20 kg, + ve sense
    C. 10 kg, + ve sense
    D. 10 kg, – ve sense
    E. 45 kg, + ve sense