InterviewSolution
Saved Bookmarks
InterviewSolution
| 1. |
Figure shows a potentiometer with a cell of 2.0 V and internal resistance `0.40 Omega` maintain a potential drop across the resistor wire AB. A standard cell which maintains a constant emf of 1.02 V (for very moderate currents upto a few mA) gives a balances point at 63.3 cm length of the wire. To ensure very low currents drawn from the standard cell, a very high resistance of `600 Omega` is put is series with it, which is shortedd close to the balance point. The standard cell is then replaced by a cell of unknown emf `epsilon` and the balance point found similarly, turns out to be at 82.3 cm length of the wire. What purpose does the high resistance of 600 k `Omega` have? |
| Answer» The purpose of using high resistance of `600 k Omega` is to allow very small current through the galvanometer when the movalbe contact is far from the balance point. | |