For a wire $$\frac{R}{\ell}=\frac{1}{2}$$ and length of wire is $$\ell=5 \mathrm{~cm}$$. If potential difference of $$\mathrm{l} \mathrm{V}$$ is applied across it, then current through wire will be ($$R=$$ Resistance)

A current of $$10 \mathrm{~A}$$ is passing through a metallic wire of cross-sectional area $$4 \times 10^{-6} \mathrm{~m}^2$$. If the density of the aluminium conductor is $$2.7 \mathrm{~gm} / \mathrm{cc}$$ considering aluminium gives 1 electron per atom for conduction, then find the drift velocity of the electrons if molecular weight of aluminium is $$27 \mathrm{~gm}$$.

A metal wire has a resistance of $$35 \Omega$$. If its length is increased to double by drawing it, then its new resistance will be

In the circuit in the figure, if no current flows through the galvanometer when the key K is closed, the bridge is balanced. The balancing condition for bridge is