Question

Consider a wire of length l, radius r, breaking stress s and breaking strength b, then what happens to breaking stress and breaking strength if, L' (new length) and r' (new radius) respectively equal: (i) 2l,r ;(ii) 2l,r/2; (iii) 2l, 2r ;(iv)l,r ;(v)l,r/2 ;(vi)l,2r ;(vii)l/2,r ;(viii)l/2,r/2 ; (ix) l/2,2r

Answer 1

Dear Student,

Breaking Stress= $\frac{BreakingStrength}{Area}$
Breaking Strength= $YA\times Strain$

(i) if length increased to 2l i.e strain=2

Initially Breaking Strength= b
New Breaking strength= 2b
​Breaking stress s=b/a
new stress= 2b/a or = 2s

similarly you do the rest.

Regards.