Make the following table for the quantities to be measured –
| Sl No. | Physical Quantity | Measured With | Least Count |
|---|
| 1 | Mass of Disc | | |
| 2 | Length of Wire | | |
| 3 | Diameter of Disc | | |
| 4 | Radius of wire | | |
| 5 | Time | | |
- Measure the mass of the disc (M) using a digital weighing machine.
- Measure the radius of the disc (R) by finding the diameter using a Vernier Calipers.
- Measure the radius of the wire (α) using a Screw Gauge
- A wire of 1 metre whose rigidity modulus (η) is to be determined is taken and the bends are straightened with the help of pliers.
- The disc is suspended from one end of the wire. The other end of the wire is passed through the chuck which is fixed to the ‘fixed stand’.
- The length of the wire between the chuck is adjusted to a convenient value (l).
- A pin is fixed vertically on the edge of the disc and a vertical pointer is placed in front of the disc against the pin to serve as a reference to count the oscillations.
- Now, apply a small torque couple and measure the time taken for 20 oscillations of the torsional oscillations.