Question

Two cells of emf ε₁ and ε₂  ( ε₁ > ε₂  ) are connected as shown in figure. When a potentiometer is connected between A and B, the balancing length of the potentiometer wire is 300 cm. On connecting the same potentiometer between A and C, the balancing length is 100 cm. The ratio is ε₁ : ε₂ is :–

(a) 3 : 1 

(b) 1 : 3 

(c) 2 : 3 

(d) 3 : 2

Answer 1

Correct option (d) 3 : 2

Explanation:

 When potentiometer is connected between A and B, then it measures only ε₁  and when coneected between A and C, then it measures ε₁ ε₂