Question

Two metallic cylinders A and B of radii (2r) and (3r)
are joined as shown in figure. If top end is fixed and
lower end is twisted by an angle theta, then angle of
twist for cylinder A is

1) 15/16 theta
2) 16/17 theta
3) 81/97 theta
4) 16/27 theta















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Answer 1

Answer:

81/97 theta will be the answer

Answer 2

Given,

Two cylinder having radii=r,2r

Let the total angle twisted is A and B.

Now,

The force applied to produce the torque on B and a restoring torque is

produce in A to counter torque of B.

This continued till both the rods does not archive the conditions of equilibrium.

Using the formula of torque in both cylinder A and B

Torque clockwise by B =torque clockwise by A

n×π(2r)4θ

2L

2

=n×π(r)4θ

L

1

θ

1

=16θ

2

Therefore,

θ

2

=

17

16θ