KCET2010PhysicsCurrent Electricity
A battery of emf E has an internal resistance r. A variable resistance R is connected to the terminals of the battery. A current i is drawn from the battery. V is the terminal potential difference. If R alone is gradually reduced to zero, which of the following best describes i and V ?
Options
- Ai approaches zero, V approaches E
- Bi approaches E r , V approaches zero
- Ci approaches E r , V approaches E
- Di approaches infinity, V approaches E
Correct answer
B. i approaches E r , V approaches zero
Step-by-step solution
Current, i = E R + r when R decreases to 0, i = E r Similarly, potential difference V=i R when R decreases to 0, ~V =0