Engineering Mechanics MCQs

Question 1

The unit of moment of inertia of an area is

Accepted Answer

m4

Answer

kg-m2

Answer

kg-m-s2

Answer

kg/m2

Question 2

The unit of work or energy in S.I. units is

Accepted Answer

Joule

Answer

Newton

Answer

Pascal

Answer

Watt

Question 3

Moment of inertia of a triangular section of base (b) and height (h) about an axis passing through its C.G. and parallel to the base, is

Accepted Answer

$$\frac{{{	ext{b}}{{	ext{h}}^3}}}{{36}}$$

Answer

$$\frac{{{	ext{b}}{{	ext{h}}^3}}}{4}$$

Answer

$$\frac{{{	ext{b}}{{	ext{h}}^3}}}{8}$$

Answer

$$\frac{{{	ext{b}}{{	ext{h}}^3}}}{{12}}$$

Question 4

The overturning of a vehicle on a level circular path can be avoided if the velocity of vehicle is __________ $$\sqrt {\frac{{{	ext{gra}}}}{{	ext{h}}}} .$$

Accepted Answer

Less than

Answer

Greater than

Answer

Equal to

Answer

None of these

Question 5

The efficiency of a screw jack is maximum, when (where $$\alpha $$ = Helix angle and $$\varphi $$ = Angle of friction.)

Accepted Answer

$$\alpha = {45^ \circ } - \frac{\varphi }{2}$$

Answer

$$\alpha = {45^ \circ } + \frac{\varphi }{2}$$

Answer

$$\alpha = {90^ \circ } + \varphi $$

Answer

$$\alpha = {90^ \circ } - \varphi $$

Question 6

Efficiency of a screw jack is given by (where $$\alpha $$ = Helix angle and $$\varphi $$ = Angle of friction.)

Accepted Answer

$$\frac{{	an \alpha }}{{	an \left( {\alpha + \varphi } ight)}}$$

Answer

$$\frac{{	an \left( {\alpha + \varphi } ight)}}{{	an \alpha }}$$

Answer

$$\frac{{	an \left( {\alpha - \varphi } ight)}}{{	an \alpha }}$$

Answer

None of these

Question 7

In a screw jack, the effort required to lift the load is given by (where W = Load lifted, α = Helix angle, and φ = Angle of friction.)

Accepted Answer

P = W tan (α + φ)

Answer

P = W tan (α - φ)

Answer

P = W tan (φ - α)

Answer

P = W cos (α + φ)

Question 8

Joule is the unit of

Accepted Answer

Work

Answer

Force

Answer

Power

Answer

Velocity

Question 9

When trying to turn a key into a lock, following is applied

Accepted Answer

Couple

Answer

Coplanar force

Answer

Non-coplanar forces

Answer

Moment