A wire stretched by 0.01 m when it is stretched by a certain force. Another wire of the same material but double the length and double the diameter is stretched by the same force. The elongation is

Options

A. 0.005m
B. 0.01m
C. 0.02m
D. 0.04m

Answer

A

Explanation

Change in length,`Deltal=(Fl)/(AY)`
Case-1 `0.01=(Fl)/(pir^(2)Y)`
Case-2: `Deltal^(') = (F.2(l))/(pi(2r)^(2)Y)`
`implies (Deltal^('))/0.01 = (2l)/l xx r^(2)/((2r)^(2)) =1/2`
`therefore Deltal^(') = .01/1 =0.005m`