Civil Engineering Applied Mechanics Quiz (or) MCQ

1 .

Kinetic friction may be defined as

A)

friction force acting when the body is in motion

B)

ratio of limiting friction and normal reaction

C)

friction force acting when the body is just about to move

D)

angle between normal reaction and resultant of normal reaction and limiting friction

Correct Answer : Option (A) : friction force acting when the body is in motion

2 .

Ball A of mass 250 g moving on a smooth horizontal table with a velocity of 10 m/s hits an identical stationary ball B on the table. If the impact is perfectly elastic, the velocity of the ball B just after impact would be___.

A)

zero

B)

5 m/sec

C)

10 m/sec

D)

None of the Above

Correct Answer : Option (C) : 10 m/sec

3 .

The centre of gravity of a homogenous body is the point at which the whole_____.

A)

volume of the body is assumed to be concentrated

B)

weight of the body is assumed to be concentrated

C)

area of the surface of the body is assumed to be concentrated

D)

All of the above

Correct Answer : Option (B) : weight of the body is assumed to be concentrated

4 .

Pick up the correct statement from the following :

A)

If two equal and perfectly elastic smooth spheres impinge directly, they interchange their velocities.

B)

If a smooth sphere impinges on another sphere, which is at rest, the latter will move along the line of centres.

C)

If two equal spheres which are perfectly elastic impinge at right angles, their direction after impact will still be at right angles.

D)

All of the above

Correct Answer : Option (D) : All of the above

Explanation : * If two equal and perfectly elastic smooth spheres impinge directly, they interchange their velocities.
* If a smooth sphere impinges on another sphere, which is at rest, the latter will move along the line of centres.
* If two equal spheres which are perfectly elastic impinge at right angles, their direction after impact will still be at right angles.
* If a sphere impinges directly on an equal sphere which is at rest, then a fraction (1 - e2) the original kinetic energy is lost by the impact.

5 .

The angular speed of a car taking a circular turn of radius 100 m at 36 km/hr will be________.

A)

1 rad/sec

B)

10 rad/sec

C)

0.1 rad/sec

D)

100 rad/sec

Correct Answer : Option (C) : 0.1 rad/sec

6 .

The angle of friction is _________.

A)

The force of friction when the body is in motion

B)

The ratio of the friction and the normal reaction

C)

The force of friction at which the body is just about to move

D)

The angle between the normal reaction and the resultant of normal raction and limiting friction

Correct Answer : Option (D) : The angle between the normal reaction and the resultant of normal raction and limiting friction

7 .

The resultant of two forces acting at right angles is 5 kgf and if they act at an angle of 60°, it is √37 kgf. The magnitudes of the forces are :

A)

3 kgf, 4 kgf

B)

4 kgf, 5 kgf

C)

5 kgf, 3 kgf

D)

None of the above

Correct Answer : Option (A) : 3 kgf, 4 kgf

8 .

A body is said to move with Simple Harmonic Motion if its acceleration, is______.

A)

Always directed away from the centre, the point of reference

B)

Proportional to the distance from the point of reference and directed towards it

C)

Inversely proportion to the distance from the point of reference

D)

Proportional to the square of the distance from the point of reference

Correct Answer : Option (B) : Proportional to the distance from the point of reference and directed towards it

9 .

The c.g. of a thin hollow cone of height h, above its base lies on the axis, at a height of_____.

A)

h / 3

B)

h / 4

C)

2h / 3

D)

3h / 4

Correct Answer : Option (C) : 2h / 3

10 .

Two forces act an angle of 120Â°. If the greater force is 50 kg and their resultant is perpendicular to the smaller force, the smaller force is______.

A)

25 kg

B)

30 kg

C)

35 kg

D)

40 kg

Correct Answer : Option (A) : 25 kg