Meter bridge is likewise called as slide wire bridge and is an instrument that chips away at the guideline(principle) of  Wheatstone bridge.

A meter bridge is utilized to track down the obscure  resistance of a conductor as that of in a Wheatstone bridge.It can likewise used to find the resistivity of the material of a wire and  the successful series and parallel  combination of resistances.

METER BRIDGE – CONSTRUCTION

The meter bridge comprises of a one-meter-long wire of uniform cross-sectional region and it has two unique areas, which is left and right segments fixed on a wooden square. One-meter-long scale is joined to the wooden square.

Two L moulded copper strips and one more copper strip are likewise fixed on that wooden square. The copper strips are fixed so that they structure two gaps to make the Wheatstone bridge. The terminal B between the holes is utilized to interface a galvanometer and a pencil jockey. The rider (jockey) which distinguishes the adjusting (balance) point.

CALCULATING THE UNKNOWN RESISTANCE

KNOWN RESISTANCE IN THE LEFT GAP AND UNKNOWN RESISTANCE IN THE RIGHT GAP

METER BRIDGE -EXPERIMENTAL SETUP 1

BALANCED CONDITION OF WHEATSTONE BRIDGE

METER BRIDGE – KNOWN & UNKNOWN RESISTANCES ARE INTERCHANGED

METER BRIDGE – EXPERIMENTAL SETUP 2

BALANCED CONDITION OF WHEATSTONE BRIDGE

Since R and l are known X can be calculated.

METER BRIDGE EXPERIMENT – PROCEDURE

Meter bridge works on the principle of Wheatstone bridge balance conditions. The circuit connections/experimental set up is shown here. Once the circuit connections are completed, the jockey is pressed near the end A and then near end B of the meter bridge wire.

A suitable value of known resistance is introduced in the dial/plug type resistance box. Select the values of known resistance R for which the balancing length is close to the middle point of the meter bridge wire. The pencil jockey is moved gently over the meter bridge wire to find the null deflection in the galvanometer.

If the deflections in the galvanometer are on one side, then there is some fault in the circuit connections. Check for double side deflections in the galvanometer.

Interchange the positions of X and R and repeat the experiment. The observed values are tabulated and the mean value of the unknown resistance can be calculated.

METER BRIDGE – TABULAR COLUMN

KNOWN RESISTANCE IN THE LEFT GAP AND UNKNOWN RESISTANCE IN THE RIGHT GAP

METER BRIDGE – FORMULA

METER BRIDGE EXPERIMENT – CALCULATION

METER BRIDGE EXPERIMENT – RESULT

The resistance of the given wire (X) = 2,919 Ohms