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Two identical cells, when connected either in parallel or in series gives same current in an external resistance 5 Ω. The internal resistance of each cell will be ______ Ω.

Asked in JEE Main 31st Jan 1st Shift 2023 · Combination of cells

Answer: 5

Step-by-step solution

Series: Iₛ=(2E)/(5+2r).

Parallel: Iₚ=E/(5+r/2)=(2E)/(10+r).

Equal currents: 5+2r=10+r.

r=5 Ω.

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