Two iron rods have their lengths in the ratio 5:3 and diameters in the ratio 2:1. When the rods are heated from  300C to 1000C  the ratio of their expansions is

given lengths ratio is l1l2 =53   ;diameters ratio is     r1r2=21   Δt=sameα=same α=∆ll∆t as Δt=sameα=same ∆l α l substitute the given ratio ∆l1∆l2=l1l2 =53 Does not depend on radius in linear expansion