Question

Explain how maxwell's needle can be used to determine the modulus of rigidity of the material of wire

Answer 1

Answer:

Explanation:Maxwell's needle apparatus is used to determine the shear modulus (η) of the material of a wire of uniform cylindrical cross section. Conventionally, a single observation is taken for each observable, and the value of η is calculated in a single shot. A modification to the above apparatus is made by varying one of the observables, namely the mass of the hollow cylinder (mh). With this modification five sets of values of mass difference (ms − mh) are taken and corresponding values of difference of the squares of time periods (T22 − T12) are plotted on the graph for calculating the value of η.

Hope it helps

Answer 2

Answer:

Maxwell's needle can be used measure the modulus of rigidity.

Explanation:

The formula for measuring modulus of rigidity is given by

$η = (2πl(m_{s} - m_{H})L^{2})/(r^{4}( T^{2} - T'^{2})$

where

• l is the length of wire
• $m_{s}$ is mass of solid cylinder
• $m_{H}$ is mass of hollow cylinder
• L is the length of maxwell needle
• r is radius of wire
• T is the time period of oscillation when solid masses are outside
• T' is the time period when solid masses are inside

Procedure

1. Measure the radius of wire by using screw gauge. This is r.
2. Measure the length of wire by meter scale. This is l.
3. Find the mass of one solid cylinder and one hollow cylinder by weighting scale. This is $m_{s}$ and $m_{H}$.
4. Find the length of Maxwell's needle by meter scale. This is L.
5. Now, apply both hollow cylinders and oscillate the maxwell needle and measure the time it takes to 10 oscillations. Note the time of 10 oscillations. Divide the time of 10 oscillations by 10 and get the time period. This is T.
6. Similarly find the time period of oscillations when solid cylinders are applied. This is T'.

So, by putting the values of all the variables value of modulus of rigidity of wire can be calculated.