When a certain weight is suspended from a long uniform wire, its length increases by `1 cm`. If the same weight is suspended from another wire of the same material and length but having a diameter half of the first one, the increases in length will be

Options

A. 0.5 cm
B. 2 cm
C. 4 cm
D. 8 cm

Answer

C

Explanation

`X=(F)/(k)"so",(X_(1))/(X_(2))=k_(2)/(k_(1))=((YA_(2))/(l))/((YA_(1))/(l))=(A_(2))/(A_(1))"So"X_(2)=(X_(1)r_(1)^(2))/(r_(2)^(2))=4X_(1)=4cm` <