Metre Bridge: Slide-Wire Bridge

In a sensitive meter bridge apparatus the bridge wire should possess ______.

Two resistances are connected in the two gaps of a meter bridge. The balance points is 20 cm from the zero end. When resistance of 15 ohm is connected in series with the smaller of the two resistances, the null point shifts to 40 cm. The smaller of the two resistances has the value (in ohm) ______.

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.

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

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 resistance of R Ω draws current from a potentiometer as shown in the figure. The potentiometer has a total resistance R_o Ω. A voltage V is supplied to the potentiometer. Derive an expression for the voltage across R when the sliding contact is in the middle of the potentiometer.

In a metre bridge, the balance point is found at a distance l₁ with resistances R and S as shown in the figure.An unknown resistance X is now connected in parallel to the resistance S and the balance point is found at a distance l₂. Obtain a formula for X in terms of l₁, l₂ and S. 

A meter bridge is balanced with a known resistance (R) in the left hand gap and an unknown resistance (S) in the right hand gap. Balance point is found to be at a distance of 1 cm from the left hand side. When the battery and the galvanometer are interchanged, balance point will ______.