

(Take Resistivity of Copper $=1.7 \times 10^{-8}\, \Omega \,{m}$, Resistivity of Aluminium $=2.6 \times 10^{-8}\, \Omega \,{m}$ )

$(A)$ The current through $P Q$ is zero.
$(B)$ $I_1=3 A$.
$(C)$ The potential at $S$ is less than that at $Q$.
$(D)$ $I _2=2 A$.