A battery consists of variable number n of identical cells, each internal resistance r, connected in series. Terminals are short-circuited and current I measured. Which I–n graph is correct? [Diagram: Image]
Options

Question

A battery consists of variable number n of identical cells, each internal resistance r, connected in series. Terminals are short-circuited and current I measured. Which I–n graph is correct? [Diagram: Image]

Options

G1 Physics · Accepted Answer

Step 1: For n cells in series, total emf = nE and total internal resistance = nr. Step 2: Short-circuit current I = nE/(nr) = E/r, independent of n. Step 3: Horizontal straight line is option C.