Question

To break a wire of one meter length, minimum 40 kg wt. is required. Then the wire of the same material of double radius and 6 m length will require breaking weight
A. 40 kg-wt
B. 80 kg -wt
C. 160 kg-wt
D. 320 kg-wt

Answer 1

Correct Answer - C
(c) Breaking force=Breaking stress `xx` area of cross-section of wire
`therefore` Breaking force `prop r^(2)`
If radius becomes doubled, then breaking force becomes 4 times i.e. `40xx4=160 kg-wt`