Engineering Mechanics (Set 1)

1. A body of mass ‘m’ moving with a constant velocity ‘v’ strikes another body of same mass moving with same velocity but in opposite direction. The common velocity of both the bodies after collision is

v

2v

4v

8v

2. The bellow figure shows the three coplanar forces P, Q and R acting at a point O. If these forces are in equilibrium, then

P/sin β = Q/sin α = R/sin ɣ

P/sin α = Q/sin β = R/sin ɣ

P/sin ɣ = Q/sin α = R/sin β

P/sin α = Q/sin ɣ = R/sin β

3. The centre of percussion of the homogeneous rod of length ‘L’ suspended at the top will be

L/2

L/3

3L/4

2L/3

4. The angle of inclination of the plane at which the body begins to move down the plane, is called

Angle of friction

Angle of repose

Angle of projection

None of these

5. Pick up wrong statement about friction force for dry surfaces. Friction force is

Proportional to normal load between the surfaces

Dependent on the materials of contact surface

Proportional to velocity of sliding

Independent of the area of contact surfaces

6. The term 'Centroid' is

The same as centre of gravity

The point of suspension

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

None of the above

7. The C.G. of a plane lamina will not be at its geometrical centre in the case of a

Right angled triangle

Equilateral triangle

Square

Circle

8. If the masses of both the bodies, as shown in the below figure, are reduced to 50 percent, then tension in the string will be

Same

Half

Double

None of these

9. The moment of inertia of a thin rod of mass ‘m’ and length ‘l’, about an axis through its centre of gravity and perpendicular to its length is

ml²/4

ml²/6

ml²/8

ml²/12

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

One point

One plane

Different planes

Perpendicular planes

Engineering Mechanics (Set 1)

Multiple Choice Questions