What is the function of a screw gauge in the experiment of determining Young’s modulus of a wire?

A.)It measures the extension in the wire.
B.)It measures the diameter of the wire.
C.)It measures the load applied.
D.)It measures the length of the wire.

Hint: Young 's numerical constant, the Young's modulus defines in only one direction the elastic properties of a solid experiencing stress or compression, like the metal rod which returns to its original duration, when it is stretched or compressed.

Complete answer:
The screw gauge is a tool used to measure a thin wire 's diameter or a sheet 's metal thickness. The frame is U-shaped and consists of a screwed spindle attached to a hinged thimble.

The screw gauge is used to determine the wire's diameter (d) so that the cross-section area is measured using the formula- .$A = \dfrac{{\pi {d^2}}}{4}$

Some other uses of screw gauge-

(i)Used in the industry, components of a machine with necessary measurements are manufactured.
(ii)The metal sheet thickness is seen in the number of the gauge. By using a screw gauge, we can know the number of a metal sheet's thickness in mm. The number of measurement instruments is 6 if, for example, the board thickness is 5.16 m. The amount of gauge would be 10 if the thickness of the sheet is 0.953 mm. Use a conversion table to identify the gauge number for different thicknesses.
(iii)This tool is known as a screw gauge since it is used for the calculation of a metal sheet or wire.
(iv)The diameter of a steel rod used in constructing a building can be found by using a screw gauge.

Hence, it is clear that option B is the correct option.

Note: Young's modulus is a measure of the capacity of a substance to tolerate length changes whether subjected to lengthwise stress or strain. The Young modulus is sometimes referred to as the elasticity modulus and is equal to the longitudinal stress divided by the strain.