A. these forces are equal
B. the lines of action of these forces meet in a point
C. the lines of action of these forces are parallel
D. B. and C. above
E. none of the above
A. if a system of coplanar forces is in equilibrium, then their algebraic sum is zero
B. if a system of coplanar forces is in equilibrium, then the algebraic sum of their moments about any point in their plane is zero
C. the algebraic sum of the moments of any two forces about any point is equal to moment of theiwesultant about the same point
D. positive and negative couples can be balanced
E. none of the above
A. their total sum is zero
B. two resolved parts in two directions at right angles are equal
C. sum of resolved parts in any two per-pendicular directions are both zero
D. all of them are inclined equally
E. none of the above
A. maximum when it acts at the center of gravity of a body
B. different at different points in its line of action
C. the same at every point in its line of action
D. minimum when it acts at the C.G. of the body
E. none of the above
A. coplanar force
B. non-coplanar forces
C. lever
D. moment
E. couple
A. centripetal force of earth
B. gravitational pull exerted by the earth
C. forces experienced by body in atmosphere
D. force of attraction experienced by particles
E. gravitational force of attraction towards the center of the earth
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
A. downwards at its upper end
B. upwards at its upper end
C. perpendicular to the wall at its upper end
D. zero at its upper end
E. none of the above
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
A. W
B. W sin (a + $)
C. Wtan(a + <|))
D. Wan(a-)
E. Wtana