A force of 500kg.wt can break a wire . What is the force necessary to break another wire of same material and same length but of half the cross sectional area.

Explanation

`F_1//A_1 = F_2//A_2` but `A_2 = A_1//2`
`therefore F_1//A_1 = (2F_2)/A_1 therefore F_2 = F_1/2 = 250kg wt`