Question

A battery of e.m.f. 10 V and internal resistance 0.5 $\Omega$ is connected across a variable resistance R. The value of R for which the power delivered in it is maximum is given by

• A. 0.5 $\Omega$
• B. 1.0 $\Omega$
• C. 2.0 $\Omega$
• D. 0.25 $\Omega$

Answer 1

The correct option is A 0.5 $\Omega$

According to maximum power theorem, the power in the circuit it maximum if the value of external resistance is equal to the internal resistance of battery. So if the value of external resistance is equal to the internal resistance of battery. i.e , $R=r=0.5\Omega$