Engineering Mechanics MCQs

Question 1

According to principle of moments

Accepted Answer

If a system of coplanar forces is in equilibrium, then the algebraic sum of their moments about any point in their plane is zero

Answer

If a system of coplanar forces is in equilibrium, then their algebraic sum is zero

Answer

The algebraic sum of the moments of any two forces about any point is equal to moment of their-resultant about the same point

Answer

Positive and negative couples can be balanced

Question 2

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

Accepted Answer

(B) and (C) above

Answer

These forces are equal

Answer

The lines of action of these forces meet in a point

Answer

The lines of action of these forces are parallel

Question 3

If two forces each equal to P in magnitude act at right angles, their effect may be neutralised by a third force acting along their bisector in opposite direction whose magnitude is equal to

Accepted Answer

√2P

Answer

2P

Answer

P/2

Answer

P/√2

Question 4

According to Lami's theorem

Accepted Answer

If three forces acting at a point are in equilibrium, each force is proportional to the sine of the angle between the other two

Answer

Three forces acting at a point will be in equilibrium

Answer

Three forces acting at a point can be represented by a triangle, each side being proportional to force

Answer

If three forces acting upon a particle are represented in magnitude and direction by the side of a triangle, taken in order, they will be in equilibrium

Question 5

Two coplaner couples having equal and opposite moments

Accepted Answer

Can not balance each other

Answer

Balance each other

Answer

Are equivalent

Answer

Produce a moment of couple

Question 6

The centre of gravity of a uniform lamina lies at

Accepted Answer

The mid point of its axis

Answer

The centre of heavy portion

Answer

The bottom surface

Answer

All of the above

Question 7

Centre of percussion is

Accepted Answer

The point of application of the resultant of all the forces tending to cause a body to rotate about a certain axis

Answer

The point of C.G.

Answer

The point of metacentre

Answer

Point of suspension

Question 8

Centre of gravity of a thin hollow cone lies on the axis at a height of

Accepted Answer

One-third of the total height above base

Answer

One-fourth of the total height above base

Answer

One-half of the total height above base

Answer

Three-eighth of the total height above the base

Question 9

The centre of percussion of the homogeneous rod of length L suspended at the top will be

Accepted Answer

2L/3

Answer

L/2

Answer

L/3

Answer

3L/4