Question

A potential difference across the terminals of a battery is $50V$ when $11A$ current is drawn and $60V$, when $1A$ current is drawn. The emf and the internal resistance of the battery are

• A. $62V,2\Omega$
• B. $63V,1\Omega$
• C. $61V,1\Omega$
• D. $64V,2\Omega$

Answer 1

The correct option is C $61V,1\Omega$

For a closed circuit cell supplies a constant current in the circuit.
For cell $E=V+Ir$
For $V=50V$
$E=50+11r$
Similarly, for $V=60V$
$E=60+r$
From equations (i) and (ii), we get
$E=61V$