Q. A cell of emf E volt with no internal resistance is connected to a wire whose cross section changes. The wire has three sections of equal length. The middle section has a radius a, whereas the radius of the outer two sections is 2a. The ratio of the potential difference across section AB to the potential difference across section CA is
(a) 5
(b) 4
(c) 1/2
(d) 1/4
Ans: (b)