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 sur-faces

Two coplanar couples having equal and op-posite moments_________________?

A. balance each other
B. produce a couple and an unbalanced force
C. are equivalent
D. produce a moment of couple

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

The center of gravity of a uniform lamina lies at_______________?

A. The center of heavy portion
B. The bottom surface
C. The mid point of its axis
D. All of the above

Center of percussion is______________?

A. The point of c.g.
B. The point of metacentre
C. The point of application of the resultant of all the forces tending to cause a body to rotate about a certain axis
D. Point of suspension

The units of moment of inertia of an area are_______________?

A. Kg m2
B. M4
C. Kg/m2
D. M3

The center of gravity of a triangle lies at the point of__________________?

A. Concurrence of the medians
B. Intersection of its altitudes
C. Intersection of bisector of angles
D. Intersection of diagonals

The possible loading in various members of framed structures are_______________?

A. Compression or tension
B. Buckling or shear
C. Shear or tension
D. All of the above

A trolley wire weighs 1.2 kg per meter length. The ends of the wire are attached to two poles 20 meters apart. If the horizontal tension is 1500 kg find the dip in the middle of the span________________?

A. 2.5 cm
B. 3.0 cm
C. 4.0 cm
D. 5.0 cm

In the equation of virtual work, following force is neglected_______________?

A. Reaction of any smooth surface with which the body is in contact
B. Reaction of a rough surface of a body which rolls on it without slipping
C. Reaction at a point or an axis, fixed in space, around which a body is con-strained to turn
D. All of the above