question_answer

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

A) 62 V, 2\[\Omega \]                         

B) 63 V, 1\[\Omega \]

C) 61 V, 1\[\Omega \]                         

D) 64 V, 2\[\Omega \]

Correct Answer: C

Solution :

For a closed circuit, cell supplies a constant current in the circuit. Equation of cell \[E=V+Ir\] For V= 50 volt \[E=50+11r\]      ?(i) Similarly for V = 60 volt \[E=60+r\]                                                   ? (ii)                                              From Eqs. (i) and (ii), we get \[r=1\Omega \] Substituting the value of r in Eq (i), we get E = 61 V.