Two cells, one of emf with internal resistance and the other of emf with internal…

PHYSICS · Single correct · A Level · Physics · Electricity · Electricity

Problem

Two cells, one of emf

2.0\,\text{V}

with internal resistance

0.3\,\Omega

and the other of emf

1.5\,\text{V}

with internal resistance

0.2\,\Omega

, are connected in series such that their emfs oppose each other. The combination is joined to a

3.0\,\Omega

resistor. What is the magnitude of the current through the resistor (take the direction of the larger emf as positive)? (a)

0.20\,\text{A}

(b)

0.57\,\text{A}

(c)

0.14\,\text{A}

(d)

0.17\,\text{A}