A metal wire is suspended vertically from a rigid support. When loaded with a weight in air, it extends by 0.4 mm and when the weight in air, it extends by 0.4 mm and when the weight is immersed completely in water, the extension is reduced to 0.2 mm. Then the relative density of the material of the suspended weight is

Options

A. `1//2`
B. `1//4`
C. 2
D. 4

Answer

C

Explanation

`(rho_(1))/(rho_(1)-rho_(2))=(l_(1))/(l_(1)-l_(2))=(0.4)/(0.4-0.2)=2`.