Two non-collinear parallel equal forces acting in opposite direction__________________?

A. Balance each other
B. Constitute a moment
C. Constitute a couple
D. Constitute a moment of couple

Which of the following is not a vector quantity __________________?

A. Weight
B. Velocity
C. Acceleration
D. Force

A heavy ladder resting on floor and against a vertical wall may not be in equilibrium, if____________________?

A. The floor is smooth, the wall is rough
B. The floor is rough, the wall is smooth
C. The floor and wall both are smooth surfaces
D. The floor and wall both are rough surfaces

If a rigid body is in equilibrium under the action of three forces, then _____________________?

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

According to principle of moments__________________?

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

A number of forces acting at a point will be in equilibrium if_____________________?

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

According to principle of transmissibility of forces, the effect of a force upon a body is_________________?

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

When trying to turn a key into a lock, following is applied _____________________?

A. coplanar force
B. non-coplanar forces
C. lever
D. moment

The weight of a body is due to ___________________?

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

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