define hooks law of elasticity. describe searle method to determine the youngs modulus of the material of the wire.

hiiii

Elasticity is the amount of stretch that an object contains. It is property by virtue of which matter keeps its shape from deforming into another.

When an external force is applied to an object the size and shape of the object may change, for example, an appropriate force is applied to a spring can elongate it. If the force ceases to act the object may restore to its original size and shape. An object is said to be elastic if it restores its original size and shape. This property of an object is known as elasticity         !!!!!

 The searle's method consists of two frames with a spirit level placed between them(the spirit level just lies on one frame while in other frame,it's placed on a screwgauge).The two frames r hung from a rigid support with two wires of same length & radius & of the materisl whose young's mod. is to b found.Then the load on one frame is kept constant while that on other one is incremented.As that frame moves down,spirit level does not remain horizontal ,then it's made horizontal by rotating the screwgauge.From the screwgauge reading we get the net strain.Then we can definately find "Y"