Consider N - n1n2 identical cells, each of emf e and internal resistance r. suppose n, cells are joined in series to form a line and n2 such lines are connected in parallel. The combination drives a current in an external resistance R.
(a) Find the current in the external resistance,
(b) Assuming that n, and n2 can be continuously varied, find the relation between n1, n2, R and r for which the current in R is maximum.