Mechanical Engineering - Machine Design - Discussion

In V belt drives, the wedging action of the belt in the groove gives high value of limiting ratio of tensions. Therefore the power transmitted by V-belts is more than flat belts for the same coefficient of friction, arc of contact and allowable tension in the belts.

So option A is also wrong.

For option D ratio is cosec β,
Where β is semi included angle of V belt.

In V belt drives, the wedging action of the belt in the groove gives high value of limiting ratio of tensions. Therefore the power transmitted by V-belts is more than flat belts for the same coefficient of friction, arc of contact and allowable tension in the belts.

So option A is also wrong.

For option D ratio is cosec β,
Where β is semi included angle of V belt.

Option D is correct because in flat belt tension ratio is 4:1 and in v-belt the ratio is 7:1.

The answer will be correct only if the question is asking about the right option because 1, 2, 3 all statements are wrong.