Question

two cell of emf 2v and 4v respectively and internal resistance 1ohm each are connected in series with emf in opposite sense the equivalent emf of the combination is​

Answer 1

Given:

Two cell of emf 2v and 4v respectively and internal resistance 1ohm each are connected in series with emf in opposite sense.

To find:

Equivalent EMF of combination?

Calculation:

First of all, since the cells are connected in series with opposite EMF sense, the net EMF will be:

$\sf \: EMF_{net} = 4 - 2 = 2 \: volts$

Now, the internal resistance of the cells are also in series combination, so net resistance will be:

$\sf r_{net} = 1 + 1 = 2 \: ohm$

So, equivalent EMF is 2 Volts with internal resistance of 2 ohm.