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For the brake shown in the figure, which one of the following is TRUE?

For the brake shown in the figure, which one of the following is TRUE? Correct Answer Self energizing for clockwise rotation of the drum

Concept:

When the frictional force helps the applied force in applying the brake, such type of brakes are said to be self-energizing brakes.

Self-energizing brake is the one in which torque due to Fr supports torque due to F.

Calculation:

Given:

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The torque due to F is clockwise. The torque due to Fr = μRN is clockwise. So, it is a self-energizing brake.

Let consider clockwise rotation

∑Mpivot = 0

F × ℓ - RN × a + μ RN × b = 0

When the wheel rotates in a clockwise direction we can see that friction is helping the applied force in applying the brake. Hence it is called a self-energizing brake.

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