The length of a wire of a potentiometer is 100 cm, and the emf of its standard cell is E volt. It is employed to measure the e.m.f of a battery whose internal resistance is 0.5 Ω Ω . If the balance point is obtained at l = 30 cm from the positive end, the e.m.f. of the battery is (where i is the current in the potentiometer)
Text Solution
Verified by ExpertsA
Let V be the potential across balance point and one end of wire. Hence according to the principle of potentiometer 
Also if a cell of emf E is employed in the circuit between the ends of potentiometer wire of length L then 
.
Prepare Smarter with CGP Edu
Get practice questions, solutions, and test series in one place.
Write a Review
Share your experience with this question and solution.
Commentary
Send your comment, doubt, correction, or feedback to admin.
Similar Questions
Explore conceptually related problems