Engineering Mechanics MCQs

Question 1

If the masses of both the bodies, as shown in the below figure, are doubled, then the acceleration in the string will be

Accepted Answer

Same

Answer

Half

Answer

Double

Answer

None of these

Question 2

The centre of percussion is below the centre of gravity of the body and is at a distance equal to

Accepted Answer

$$\frac{{{	ext{k}}_{	ext{G}}^2}}{{	ext{h}}}$$

Answer

$$\frac{{	ext{h}}}{{{{	ext{k}}_{	ext{G}}}}}$$

Answer

$$\frac{{{{	ext{h}}^2}}}{{{{	ext{k}}_{	ext{G}}}}}$$

Answer

$${	ext{h}} 	imes {{	ext{k}}_{	ext{G}}}$$

Question 3

The coefficient of friction depends on

Accepted Answer

Nature of surface

Answer

Area of contact

Answer

Shape of surfaces

Answer

Strength of surfaces

Question 4

A lead ball with a certain velocity is made to strike a wall, it falls down, but rubber ball of same mass and with same velocity strikes the same wall, it rebounds. Select the correct reason from the following:

Accepted Answer

The change in momentum suffered by rubber ball is more than the lead ball

Answer

Both the balls undergo an equal change in momentum

Answer

The change in momentum suffered by rubber ball is less than the lead ball

Answer

None of the above

Question 5

The moment of inertia of a solid cylinder of mass 'm', radius 'r' and length '$$l$$' about the longitudinal axis or polar axis is

Accepted Answer

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

Answer

$$\frac{{{	ext{m}}{{	ext{r}}^2}}}{4}$$

Answer

$$\frac{{{	ext{m}}{{	ext{r}}^2}}}{6}$$

Answer

$$\frac{{{	ext{m}}{{	ext{r}}^2}}}{8}$$

Question 6

In a framed structure, as shown in the below figure, the forces in the members AB and BC are respectively

Accepted Answer

$$\sqrt 3 \,\,$$W (tensile) and 2W (compressive)

Answer

2W (tensile) and $$\sqrt 3 \,\,$$W (compressive)

Answer

$$2\sqrt 3 \,\,$$W (tensile) and $$2\sqrt 3 \,\,$$W (compressive)

Answer

None of the above

Question 7

Forces are called coplanar when all of them acting on body lie in

Accepted Answer

One plane

Answer

One point

Answer

Different planes

Answer

Perpendicular planes

Question 8

When a body of mass moment of inertia '$$I$$' (about a given axis) is rotated about that axis with an angular velocity to, then the kinetic energy of rotation is

Accepted Answer

$$0.5I{\omega ^2}$$

Answer

$$I\omega $$

Answer

$$I{\omega ^2}$$

Answer

$$0.5I\omega $$

Question 9

The minimum force required to slide a body of weight 'W' on a rough horizontal plane is

Accepted Answer

W tanθ

Answer

W sinθ

Answer

W cosθ

Answer

None of these