Toluene reacts with bromine in the presence of light to give benzyl bromide while in presence of `Fe Br_3` ,it gives p-bromotoluene give explanation for the above observation.

Explanation

In presence of light, side chain is attacked to produce benzyl bromide,
FIGURE
In presence of Fe .B r_3, B r^2. produces .B r^4. (electio phile) which attacks the benzene ring at o, P - position to give P - bromotoluene.