Question

Which of the following statements are not true?

(a) Increasing pressure angle improves the tooth strength

(b) Contact duration is decreased with increase in pressure angle

(c) 20⁰ pressure angle has quieter operation then 14.5⁰

(d) All of the statements are true

This question was asked to me in an oral examination.

This exercise is from the System of Gear Tooth unit in module Rolling Contact Bearings, Spur Gears and Helical Gears of Machine Design

Answer 1

The optimal answer is (c) 20⁰ pressure angle has quieter operation then 14.5⁰

Expand on the concept with: Lower the pressure angle, quieter is the operation. Lower the pressure angle, lower is the breadth of the tooth at root.