Shaalaa.com | Meter bridge and Potentiometer
Instrument which can measure terminal potential difference as well as electro motive force (e.m. f.) is................................
- Wheatstone’s meter bridge
Accuracy of potentiometer can be easily increased by ______
(A) increasing resistance of wire
(B) decreasing resistance of wire
(C) increasing the length of wire
(D) decreasing the length of wire
A potentiometer wire has a length of 4 m and a resistance of 5 Ω. What resistance should be connected in series with a potentiometer wire and a cell of e.m.f. 2 V having internal resistance 1 Ω to get a potential gradient of 10-3 V/cm ?
When a resistance of 12 ohm is connected across a cell, its terminal potential difference is balanced by 120 cm length of potentiometer wire. When the resistance of 18 ohm is connected across the same cell, the balancing length is 150 cm. Find the balancing length when the cell is in open circuit. Also calculate the internal resistance of the cell.
In potentiometer experiment, if l1 is the balancing length for e.m.f. of cell of internal resistance r and l2 is the balancing length for its terminal potential difference when shunted with resistance R then :
A cell balances against a length of 200 cm on a potentiometer wire, when it is shunted by a resistance of 8Ω. The balancing length reduces by 40 cm, when it is shunted by a resistance of 4 Ω . Calculate the balancing length when the cell is in open circuit. Also calculate the internal resistance of the cell.