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) \[62V,2\Omega \]          

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

C) \[61V,1\Omega \]   

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

Correct Answer: C

Solution :

  For a closed circuit, cell supplies a constant current in the circuit                 Equation of cell \[=0.05\Omega \]                      For  V = 50 V                     ....(1)                     E = 50 + 11r            Similarly, for V = 60V                     E 60 + r                               ....(ii) From Eqs. (i) and (ii), we get                  E = 61 V