ENGINEERING MECHANICS QUIZ

Efficiency of a screw jack is given by (where α = Helix angle, and φ = Angle of friction.)

tanα/tan (α + φ)

tan(α - φ)/tanα

tan(α + φ)/tanα

None of these

TRUE ANSWER : ?
YOUR ANSWER : ?

The ratio of limiting friction and normal reaction is known as

Sliding friction

Angle of repose

Coefficient of friction

Angle of friction

TRUE ANSWER : ?
YOUR ANSWER : ?

The potential energy of a vertically raised body is __________ the kinetic energy of a vertically falling body.

None of these

Less than

Equal to

Greater than

TRUE ANSWER : ?
YOUR ANSWER : ?

Two forces are acting at an angle of 120°. The bigger force is 40 N and the resultant is perpendicular to the smaller one. The smaller force is

40 N

20 N

None of the listed here

120 N

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YOUR ANSWER : ?

The moment of inertia of a solid sphere of mass ‘m’ and radius ‘r’ is

2mr²/5

mr²

mr²/2

2mr²/3

TRUE ANSWER : ?
YOUR ANSWER : ?

Tension in the cable supporting a lift is more when the lift is moving __________ with an acceleration.

Horizontal

Upwards

None of these

Downwards

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YOUR ANSWER : ?

Non-coplanar non-concurrent forces are those forces which

None of these

Do not meet at one point and their lines of action do not lie on the same plane

Meet at one point, but their lines of action do not lie on the same plane

Do not meet at one point but their lines of action lie on the same plane

TRUE ANSWER : ?
YOUR ANSWER : ?

An ideal machine is one whose efficiency is

1

Between 70 and 80%

Between 60 and 70 %

Between 80 and 90%

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YOUR ANSWER : ?

A rubber ball is dropped from a height of 2 m. If there is no loss of velocity after rebounding, the ball will rise to a height of

4 m

3 m

2 m

1 m

TRUE ANSWER : ?
YOUR ANSWER : ?

The efficiency of a lifting machine is the ratio of

Output to the input

All of these

Mechanical advantage to the velocity ratio

Work done by the machine to the work done on the machine

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YOUR ANSWER : ?