Metre Bridge: Slide-Wire Bridge

Why is it generally preferred to obtain the balance point in the middle of the meter bridge wire?

The instrument which can measure terminal potential difference as well as electromotive force (e.m. f.) is ______ 

1. Wheatstone’s meter bridge
2. Voltmeter
3. Potentiometer
4. Galvanometer

When a metal conductor connected to left gap of a meter bridge is heated, the balancing point ______.

An I0m long uniform metallic wire having a resistance of 20Ω IS used as a  potentiometer wire. This wire is connected in series with another resistance of 480Ω
and a battery of emf 5V having negligible internal resistance. If an unknown emf e is balanced across 6m of the potentiometer wire, calculate

1) the potential gradient across the potentiometer wire

2) the value of the unknown emf e.

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 ?

State any ‘two’ possible sources of errors in meter-bridge experiment. How can they be minimised?

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 :

The figure shows experimental set up of a meter bridge. When the two unknown resistances X and Y are inserted, the null point D is obtained 40 cm from the end A. When a resistance of 10 Ω is connected in series with X, the null point shifts by 10 cm. Find the position of the null point when the 10 Ω resistance is instead connected in series with resistance ‘Y’. Determine the values of the resistances X and Y.