Practice portal › Current Electricity › Cells, EMF and Internal Resistance

Two cells are connected between points A and B as shown. Cell 1 has emf of 12 V and internal resistance of 3 Ω. Cell 2 has emf of 6 V and internal resistance of 6 Ω. An external resistor R of 4 Ω is connected across A and B. The current flowing through R will be ______ A. [Figure: cell 1 (12 V, 3 Ω) and cell 2 (6 V, 6 Ω) in parallel between terminals A (left) and B (right). Cell 1 has its positive plate towards A; cell 2 has its positive plate towards B, so they oppose.]

Asked in JEE Main 25th Jan 2nd Shift 2023 · Combination of cells

Figure: Combination of cells
Answer: 1

Step-by-step solution

The cells are in parallel with opposite polarity: E_eq=(12/3-6/6)/(1/3+1/6)=3/(0.5)=6 V.

r_eq=(3×6)/(3+6)=2 Ω.

I=6/(2+4)=1 A.

More Cells, EMF and Internal Resistance questionsAll Cells, EMF and Internal Resistance questions →

Reading this solution needs no sign-in. You only sign in to practise against the clock and keep your progress.

Practise this with a timer