Current Electricity

Two wires \(A\) and \(B\) are made up of the same material and have the same mass. Wire \(A\) has radius of \(2.0 \mathrm{~mm}\) and wire \(B\) has radius of \(4.0 \mathrm{~mm}\). The resistance of wire \(B\) is \(2 \Omega\). The resistance of wire \(A\) is ________ \(\Omega\).