Holding force constant, what will be the effect of increasing the Moment arm?

(a) Depends on the direction of the force.

(b) Torque will increase.

(c) Torque is constant.

(d) Torque will decrease.

(e) The direction of rotation will change.

(b) Torque will increase.

Explanation:

Torque is given as the product of force and moment arm (radius).

τ = F x r

F = τ / r

where;

F is force

τ is torque

r is radius (moment arm)

Keeping force constant, we will have the following;

τ ∝ r

This shows that torque is directly proportional moment arm (radius), thus increase in moment arm, will cause increase in torque.

For instance;

let the constant force = 5 N

let the initial moment arm, r = 2m

Torque, τ = 5 N x 2m = 10 Nm

When the moment arm is increased to 4 m

Torque, τ = 5 N x 4m = 20 Nm

Therefore, at a constant force, increasing in the Moment arm, will cause increase in torque.

Coorect option is " (b) Torque will increase."