Chemistry Question from JEE Main 2023 · 15 April, Shift 1

For a reversible reaction $\mathrm{A \rightleftharpoons B}$, the $\Delta H_{forward\ reaction} = 20\ \mathrm{kJ\,mol^{-1}}$. The activation energy of the uncatalysed forward reaction is $300\ \mathrm{kJ\,mol^{-1}}$. When the reaction is catalysed keeping the reactant concentration same, the rate of the catalysed forward reaction at $27^\circ\mathrm{C}$ is found to be same as that of the uncatalysed reaction at $327^\circ\mathrm{C}$. The activation energy of the catalysed backward reaction is _____ $\mathrm{kJ\,mol^{-1}}$.