Question

A disc suspended by a wire, which twists first in one direction and then in the reverse direction,
in the horizontal plane. How this method is used to determine the :
a) Moment of inertia of the
disc and
b) Rigidity modulus of the wire using moment of inertia.

Answer 1

Answer:

this is a torsional pendulum

Explanation:

The radius of the suspension wire is measured using a screw gauge.

2. The length of the suspension wire is adjusted to suitable values like

0.3m,0.4m,0.5m,.....0.9m,1m etc.

3. The disc is set in Oscillation. Find the time for 20 oscillations twice and

determine the mean Period of oscillation ' T0 '.

4. The two identical masses are placed symmetrically on either side of the

suspension wire as Close as possible to the centre of the disc, and measure

d1 which is the distance between the Centres of the disc and one of the

identical masses.

5. Find the time for 20 oscillations twice and determine the mean period

of oscillation ' T1 '.

6. The two identical masses are placed symmetrically on either side of the

suspension wire as Far as possible to the centre of the disc, and measure

d2 which is the distance between the Centres of the disc and one of the

identical masses.

7. Find the time for 20 oscillations twice and determine the mean period of

oscillation ' T2 '.

8. Find the moment of inertia of the disc using the given formulae.