A battery with EMF E and internal resistance r is connected across a resistance R. The power consumption in R will be maximum when :
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Question

A battery with EMF E and internal resistance r is connected across a resistance R. The power consumption in R will be maximum when :

G1 Physics · Accepted Answer

The current in the circuit is I = E/(R + r). Power consumed in the load resistance R is P = I²R = E²R/(R + r)². According to the maximum power transfer condition, the load receives maximum power when the load resistance equals the internal resistance of the source: R = r. Correct option: D.