An ideal transformer with purely resistive load operates at $12 ~\mathrm{kV}$ on the primary side. It supplies electrical energy to a number of nearby houses at $120 \mathrm{~V}$. The average rate of energy consumption in the houses served by the transformer is 60 $\mathrm{kW}$. The value of resistive load $(\mathrm{Rs})$ required in the secondary circuit will be ___________ $\mathrm{m} \Omega$.