Question

24. Figure shows mixed grouping of identical dels each of emf 4 V and internal resistance 1 This combination
can be replaced by an equivalent cell between A and B having e.mf. E and internal resistancer, where
HHHH
HHH
HE
R
A
B
(1) E = 72V, r = 18 2
(3) E = 72V, r = 22
(2) E= 24V, r = 18 2
(4) E= 24V, r = 29​

Answer 1

Series :

EMF of each cell = 4 volt

For n no of cells connected in series the EMF of the cell is given by the formula

$\implies{E \: s = nE}$

here ,

n represents total no of cells connected in series

$\implies{E \: s = 6 \times 4}$

$\implies{E \: s =24V}$

The internal resistance for the cells connected in series is given by the formula ,

$\implies{r \: s = nr}$

here ,

n represents total no of cells connected in series

internal resistance of each cell = 1 ohm

$\implies{r \: s =6 \times 1}$

$\implies{r \: s =6 \: ohm}$

Parallel :

The EMF of all the cells connected in parallel combination is equal to the EMF produced by a single row

EMF through all the three rows is the same

hence we can conclude that ,

$\implies{E \: s =E \: p}$

$\boxed{E \: p = 24V}$

n number of cells are connected in series in m number of rows

where ,

m = 3 , n = 6

So the internal resistance of the combination is given by the formula

$\implies{rp \: = \frac{nr}{m} }$

$\implies{rp \: = \frac{rs}{m} }$

$\implies{rp \: = \frac{6}{3} }$

$\boxed{rp = 2 \: ohm}$

Answer 2

Explanation:

Hope this will help you