Question

To get maximum current in resistance of $3\Omega$, one can use $n$ parallel rows of $m$ cells each connected in series. If the total no. of cells is $24$ and the internal resistance is $0.5$ ohm then:

• A. $m=12,n=2$
• B. $m=8,n=3$
• C. $m=2,n=12$
• D. $m=6,n=4$

Answer 1

The correct option is A $m=12,n=2$

Equivalent Resistance = $\frac{3\left(m\right)}{n}$

Now the circuit will become as shown in the figure (2).

Current = $I=\frac{V}{0.5+\frac{3m}{n}}=\frac{Vn}{n+6m}$

Now check the options to get the pair in which maximum current is obtained.