Question

To get maximum current through a resistance of 2.5, one can use m rows of cells, each row having n cells. The internal resistance of each cell is 0.5. What are the values of n and m if the total number of cells is 45?​

Answer 1

Answer:

Resistance=2.5Ω Internal resistance =0.5Ω,mn=45

Let n be the cell in the series in one row and m rows in parallel let all the cells are identical. Let each cell be of emf E and internal resistance is r,

In each row of cell in parallel so, total internal resistance (r_p) of all the cell given by,

r

p

1

=

n

r

1

+

n

r

1

+.....n terms

n

r

m

⇒r

p

=

m

n

r

Total distance in the circuit R+

m

n

r

Effective emf of the cell is nE

I=

R+

m

n

r

nE

=

mR+n

r

mnE

The current will maximum if, MR=n

r

,⇒R=n

r

.m

n

=45...1

m×2.5=n×0.5⇒n=5m...........2

From equation 1 and 2 we get,

m

2

=45⇒m

2

=9⇒m=3

Therefore, n=15;m=3

solution

Answered By

toppr

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