Question

if n electrical cells each EMF 'E' is connected in series then find efficient EMF​

Answer 1

Given:

n electrical cells each EMF 'E' is connected in series.

To find:

Effective EMF of the combination of cells.

Calculation:

Lets assume that all the cells have been connected with same polarities.

So, Let effective EMF be E_(eff):

In case of series combination:

$\sf \therefore \: E_{eff} = \sum(E_{i})$

$\sf \implies \: E_{eff} = E + E + .... \: n \: times$

$\boxed{ \sf \implies \: E_{eff} = nE}$

However, if alternate cells are connected with opposite polarities, then :

$\sf \therefore \: E_{eff} = \sum(E_{i})$

$\sf \implies \: E_{eff} = E - E + E - .... \: n \: times$

Now, if n is even:

$\sf \implies \: E_{eff} = E - E + E - .... \: n \: times$

$\sf \implies \: E_{eff} = 0$

Now, if n is odd:

$\sf \implies \: E_{eff} = E - E + E - .... \: n \: times$

$\sf \implies \: E_{eff} = E$

Hope It Helps