This Torsion Pendulum – Disc Type is a precision physics laboratory apparatus used to study torsional oscillations and determine the modulus of rigidity of a suspension wire. It provides a clear practical demonstration of angular oscillatory motion and the elastic behavior of a wire under twisting force.

 The apparatus consists of a solid brass circular disc of approximately 125 mm diameter and 0.50 mm thickness, suspended with the help of a wire connected between a universal clamp and a pin-vice fixed on the disc. A heavy brass ring of the same diameter is also provided, which can be placed on the disc to increase the moment of inertia and observe the change in time period.

 By measuring the time period of torsional vibrations, students can calculate the modulus of rigidity and understand the relationship between moment of inertia, angular displacement, and torsional motion. This apparatus is suitable for schools, colleges, universities, and advanced physics laboratories.

 Experimental Objectives

 To study torsional oscillations using a disc-type torsion pendulum.
To determine the modulus of rigidity of the suspension wire.
To observe the effect of change in moment of inertia on the time period of oscillation.
To understand the elastic behavior of a wire under torsional motion.