Question

Two metallic cylinder made of same material and radius r and 2r are joined

Answer 1

The question is incomplete.

However,

Given:

Two metallic cylinders,

Radius of cylinder 1 = r

Radius of cylinder 2 = 2r

To find:

The twist

Solution:

Clockwise torque produced by cylinder 2 =  Anticlockwise torque produced by cylinder 1

Torque = η π ( r )^4 θ2 / 2 l

Substituting and equating,

We get,

η π ( 2r )^4 θ2 / 2 l = η π ( r )^4 θ2 / 2 l

θ1 = 16 θ2

Twisted angle = θ1 + θ2

Substituting,

θ2 + 16 θ2 = θ

Hence, The angle of twist,

θ1 = 16 / 17 θ

θ2  = θ / 17