Question

N identical cells, each of emf ℰ and internal resistance r, are joined in series. Out of these, n cells are wrongly connected, i.e., their terminals are connected in reverse of that required for series connection. n < N/2. Let ℰ₀ be the emf of the resulting battery and r₀ be its internal resistance,

(a) ℰ₀ = (N - n)ℰ, r₀ = (N - n)r 

(b) ℰ₀ = (N - 2n)ℰ, r₀ = (N - 2n)r 

(c) ℰ₀ = (N - 2n)ℰ, r₀ = Nr 

(d) ℰ₀ = (N - n)ℰ, r₀ = Nr

Answer 1

Correct Answer is: (c) ℰ₀ = (N - 2n)ℰ, r₀ = Nr