On mixing impurities, the elasticity of a material

Options

A. decreases
B. increases
C. sometimes increases and sometimes decreases
D. remains same

Answer

C

Explanation

`y=("stress")/("strain") therefore "strain"=(10^(9))/(2xx10^(11)) =0.5 xx10^(-2)`
`therefore (Delta r)/(r ) = 0.5 xx10^(-2)`
`therefore Delta r = 2.8 xx 0.5 xx 10^(-2) = 14 xx 10^(-3) A^(@)`.