Question

as shown in the circuit, if all the cells are identical, each of emf E and internal resistance r, for the maximum power developed in the circuit value of the internal resistance r must be​

Answer 1

Answer:

option 3

Explanation:

3rd option is correct

Answer 2

Answer:

Option D

Explanation:

For the maximum power to be deliver, we used the thevenin maximum power theorem which states that for maximum power to be delivered, load resistance should be equal to internal resistance.

Now if we take the equivalent resistance of cells in parallel branch, then net resistance is;

Req = r/4

And if we take the combination of parallel and series cells, net resistance comes as;

r eq = 4/9 r

Hence the external resistance should be equal to 4/9r