Question

$ (i) $ For the Searle’s experiment, in the graph shown, there are two readings $ a $ and $ b $ that are not lying on the straight line.
 $ (ii) $ Experiment is not performed precisely.

(A) Both $ (i) $ and $ (ii) $ are true and $ (ii) $ is the reason for $ (i) $
(B) Both $ (i) $ and $ (ii) $ are true and $ (ii) $ is not the reason for $ (i) $
(C) Only $ (i) $ is true
(D) Only $ (ii) $ is true

Answer 1

Hint :Searle’s experiment is used to find the Young’s modulus of elasticity of the material. It is explained as: Searle’s apparatus consists of two wires having equal lengths and these wires are attached to the rigid support and both the vertical wires are attached by the horizontal bar in the end of both wires out of which one is the test wire and the other is control or reference wire. When the load is applied on a test wire, that wire gets elongated and there is a tilt by a small amount. This tilt is measured and adjusted by turning the screw of the micrometer. And plot these readings on the graph. We observe that the readings we have obtained at different levels is in straight line passing through the origin. So we have seen that the graph between load and extension must be straight and passing through the origin.

Complete Step By Step Answer:
According to Searle's experiment, this apparatus is used to find the young’s modulus of the elasticity of the given material. And it is also compulsory according to the result of this experiment we know that the graph must be in a straight line and passing through the origin.
Now, let us discuss the above two points.
Point $ (i) $ states that the two points are not in straight line as shown in the graph above
Point $ (ii) $ states that the experiment is not performed properly.
Thus, we have concluded that both are true and $ (ii) $ is the proper reason for $ (i) $ .
The correct option is A.

Note :
You must study the concept of Searle’s experiment and observe the graph if given and also the statements given if all are according to the proper concept of Searle’s experiment then the statements are true. Searle’s experiment is mainly used to find the elasticity of the material allotted.