Q. The potential difference across the terminals of a battery is $50V$ when $11A$ current is drawn and $60V$ when $1A$ current is drawn. The $e.m.f.$ and the internal resistance of the battery are
A) $62V,\ 2\Omega$
B) $63V,\ 1\Omega$
C) $61V,\ 1\Omega$
D) $64V,\ 2\Omega$
Explanation
(c) Given $V_{1} = 50\ volt,\ i_{1} = 11A;V_{2} = 60\ volt,\ i_{2} = 1A$
If $e.m.f.$ and internal resistance of battery are $E$ and $r$ respectively then $P.D.$ across terminals of battery,
$V = E - ir$
We have $50 = E - 11r$ …(i)
And $60 = E - 1r$ …(ii)
From (i) and (ii),
$E = 61V$ and $r = 1\Omega$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.