The tension on the slack side of the belt is __________ the tension on the tight side of the belt.

In a band and block brake, the ratio of tensions on tight side and slack side of the band is (where $$\mu $$ = Coefficient of friction between the blocks and the drum, $$\theta $$ = Semi-angle of each block subtending at the center of drum and n = Number of blocks)

A

$$\frac{{{{\text{T}}_1}}}{{{{\text{T}}_2}}} = \mu \theta {\text{n}}$$

B

$$\frac{{{{\text{T}}_1}}}{{{{\text{T}}_2}}} = {\left( {\frac{{1 - \mu \tan \theta }}{{1 + \mu \tan \theta }}} \right)^{\text{n}}}$$

C

$$\frac{{{{\text{T}}_1}}}{{{{\text{T}}_2}}} = {\left( {\mu \theta } \right)^{\text{n}}}$$

D

$$\frac{{{{\text{T}}_1}}}{{{{\text{T}}_2}}} = {\left( {\frac{{1 + \mu \tan \theta }}{{1 - \mu \tan \theta }}} \right)^{\text{n}}}$$

In a band and block brake, the ratio of tensions on the tight and slack sides of band is given by (where $$\mu $$ = Coefficient of friction between the blocks and the drum, $$\theta $$ = Semi-angle of each block subtending at the centre of drum and n = Number of blocks)

A

$$\frac{{{{\text{T}}_1}}}{{{{\text{T}}_{\text{2}}}}} = \mu \theta \times {\text{n}}$$

B

$$\frac{{{{\text{T}}_1}}}{{{{\text{T}}_2}}} = {\left( {\mu \theta } \right)^{\text{n}}}$$

C

$$\frac{{{{\text{T}}_1}}}{{{{\text{T}}_2}}} = {\left( {\frac{{1 - \mu \tan \theta }}{{1 + \mu \tan \theta }}} \right)^{\text{n}}}$$

D

$$\frac{{{{\text{T}}_1}}}{{{{\text{T}}_2}}} = {\left( {\frac{{1 + \mu \tan \theta }}{{1 - \mu \tan \theta }}} \right)^{\text{n}}}$$

The power transmitted by a belt is maximum when the maximum tension in the belt is _________ of centrifugal tension.

A

One-third

B

Two-third

C

Double

D

Three times

When the belt is stationary, it is subjected to some tension known as initial tension. The value of this tension is equal to the

A

tension in the tight side of the belt

B

tension in the slack side of the belt

C

sum of the tensions on the tight side and slack side of the belt

D

average tension of the tight side and slack side of the belt

In a belt drive, if the pulley diameter is doubled keeping the tension and belt width constant, then it will be necessary to

A

Increase the key length

B

Increase the key depth

C

Increase the key width

D

Decrease the key length

In a belt drive, the pulley diameter is doubled, the belt tension and pulley width remaining same. The changes required in key will be

A

Increase key length

B

Increase key depth

C

Increase key width

D

Double all the dimensions

If d is the normal diameter of a bolt in mm, then the initial tension in kg in a bolt used for making a fluid tight joint as for steam engine cover joint is calculated by the relation

A

124 d

B

138 d

C

151 d

D

168 d

The initial tension (in newtons) in a bolt used for making a fluid tight joint like steam engine cover joints, is calculated by the relation (where d = Nominal diameter of bolt in mm)

A

1420 d

B

1680 d

C

2080 d

D

2840 d

The ratio of driving tensions in V-belt drives is __________ flat belt drives.

A

Equal to

B

sin$$\,\alpha $$ times more than

C

sin$$\,\alpha $$ times less than

D

cosec$$\,\alpha $$ times more than

The stretching in a belt can be controlled by __________ the stress in the belt.

A

Reducing

B

Increasing

C

Both A and B

D

None of these

The tension on the slack side of the belt is __________ the tension on the tight side of the belt.

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