Engineering Mechanics MCQs

Question 1

According to law of triangle of forces

Accepted Answer

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

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

Question 2

A smooth cylinder lying on its convex surface remains in __________ equilibrium.

Accepted Answer

Unstable

Answer

Stable

Answer

Neutral

Answer

None of these

Question 3

Center 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 metacenter

Answer

Point of suspension

Question 4

The linear velocity of a body rotating at $$\omega $$ rad/s along a circular path of radius r is given by

Accepted Answer

$$\omega {	ext{r}}$$

Answer

$$\frac{\omega }{{	ext{r}}}$$

Answer

$$\frac{{{\omega ^2}}}{{	ext{r}}}$$

Answer

$${\omega ^2}{	ext{r}}$$

Question 5

During elastic impact, the relative velocity of the two bodies after impact is __________ the relative velocity of the two bodies before impact.

Accepted Answer

Equal and opposite to

Answer

Equal to

Answer

Less than

Answer

Greater than

Question 6

For a self locking machine, the efficiency must be

Accepted Answer

Less than 50%

Answer

Equal to 50%

Answer

Greater than 50%

Answer

100%

Question 7

Coefficient of friction depends upon

Accepted Answer

Nature of surface only

Answer

Area of contact only

Answer

Both (A) and (B)

Answer

None of these

Question 8

Coefficient of friction is the

Accepted Answer

Ratio of limiting friction and normal reaction

Answer

Angle between normal reaction and the resultant of normal reaction and the limiting friction

Answer

The friction force acting when the body is just about to move

Answer

The friction force acting when the body is in motion

Question 9

Pick up the incorrect statement from the following:

Accepted Answer

The C.G. of a semicircle is at a distance of $$\frac{{	ext{r}}}{2}$$ from the centre

Answer

The C.G. of a circle is at its centre

Answer

The C.G. of a triangle is at the intersection of its medians

Answer

The C.G. of a rectangle is at the intersection of its diagonals