Q: If the ratio of lengths, radii and Young’s moduli of steel and brass wires are *a*, *b* and c respectively, their respective loads are in the ratio 3 : 2, then the corresponding ratio of increase in their lengths would be

(a) $ \displaystyle \frac{2 a^2 c}{b} $

(b) $ \displaystyle \frac{3 a}{2 b c} $

(c) $ \displaystyle \frac{3 a c}{b^2} $

(d) $ \displaystyle \frac{3 c}{2 a b^2} $

Ans: (b)