Question

Find the value of $R$, such that maximum power is transfereed to it.

• A. $1\Omega$
• B. $2\Omega$
• C. $3\Omega$
• D. $6\Omega$

Answer 1

The correct option is A $1\Omega$

We can observe that these two cells are in parallel combination. So, equivalent resistance is given by,

$r_{eq}=\frac{r_1{r}_2}{r_1+r_2}=\frac{2\times 2}{2+2}=1\Omega$

So, reduced circuit can be drawn as shown below :
From maximum power transfer theorem we know that output resistance should be equal to internal resisatnce for maximum power transfer.

$\therefore R=1\Omega$

Why this question: Tip : For this type of question reduce the circuit diagram to one battery and external resistance Tip: Observe that, we do not need to find equivalent emf to find the final answer. So, we can save our time if we observe carefully what data is neded to answer the question.