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

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

Which of the following is not a vector quantity __________________?

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

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

The forces, which meet at one point, but their lines of action do not lie in a plane, are called_________________?

A. Coplanar non-concurrent forces
B. Non-coplanar concurrent forces
C. Non-coplanar non-concurrent forces
D. Intersecting forces

Which of the following is a vector quantity___________________?

A. Energy
B. Mass
C. Momentum
D. Angle

According to law of triangle of forces __________________ ?

A. Three forces acting at a point will be in equilibrium
B. Three forces acting at a point can be represented by a triangle, each side being proportional to force
C. If three forces acting upon a patticle are represented in magnitude and direction by the sides of a triangle, taken in order, they will be in equilibrium
D. If three forces acting at a point are in equilibrium, each force is proportional to the sine of the angle between the other two

D’ Alembert’s principle is used for______________________?

A. Reducing the problem of kinetics to equivalent statics problem
B. Determining stresses in the truss
C. Stability of floating bodies
D. Designing safe structures

According to Lami’s theorem___________________?

A. Three forces acting at a point will be in equilibrium
B. Three forces acting at a point can be represented by a triangle, each side being proportional to force
C. If three forces acting upon a particle are represented in magnitude and direction by the sides of a triangle, taken in order, they will be in equilibrium
D. If three forces acting at a point are in equilibrium, each force is proportional to the sine of the angle between the other two

The product of either force of couple with the arm of the couple is called_________________?

A. Resultant couple
B. Moment of the forces
C. Resulting couple
D. Moment of the couple