Question

Which of the following statements is/are correct ?
A. If `n` identical cells are connected in series and then battery thus formed , is short circuited by a conduction wire current through the wire will be independent of `n`
B. If `n` identical cells are connected in parallel and then battery than formed , is short circuited by a conducting wire current through the wire will be proportional of `n`
C. If `n` identical cells are connected in parallel are then battery thus formed , is short circuited by a wire having a current through the current through wire will be increase as `n` increases
D. none of these

Answer 1

Correct Answer - a,b,c
Let E be the emf and internal of each cell
In series, current `I = (dE)/(nr) = (E )/(r)`, (independent of n)
In parallel current `I = (E )/(nr) = (nE)/(r) , (i.e. 1 prop n)`
When n parallel cells are short circuit by a wire of constant resistance R the current
`I = (E )/((R + r//n)) = (nE)/(nR+r)`
(i.e. as n increases `I` increases)