How do you find the resistance of a wire using a meter bridge?

Connect resistance box of low range in the left hand gap between A and B. Make all the other connections as shown in the circuit diagram. Take out some resistance (say 2 ohm) from the resistance box, plug the key K. Touch the jockey gently first at left end and then at right end of the bridge wire.

How do you use a Wheatstone bridge?

The Wheatstone bridge works on the principle of null deflection, i.e. the ratio of their resistances are equal and no current flows through the circuit. Under normal conditions, the bridge is in the unbalanced condition where current flows through the galvanometer.

How a meter bridge can be used to measure resistivity of a material?

Specific Resistance of the Material of a Wire using Meter Bridge and Post Office Box. The resistance of a wire of length l and diameter D is given by R=ρlA=4ρlπD2, R = ρ l A = 4 ρ l π D 2 , where ρ is resistivity (or specific resistance) of the material of the wire.

Why are Wheatstone bridges used to measure strain?

Strain gages are configured in Wheatstone bridge circuits to detect small changes in resistance. The Wheatstone bridge is the electrical equivalent of two parallel voltage divider circuits. The output of a Wheatstone bridge, Vo, is measured between the middle nodes of the two voltage dividers.

How many resistance are used in Wheatstone bridge?

four resistances
This bridge consists of four resistances P, Q, R and S connected along four sides of a square (say ABCD) shaped circuit.

How do you use Wheatstone bridge to find unknown resistance?

Wheatstone bridge circuit diagram. The unknown resistance Rx is to be measured; resistances R1, R2 and R3 are known, where R2 is adjustable. When the measured voltage VG is 0, both legs have equal voltage ratios: R2/R1 = Rx/R3 and Rx= R3R2/R1.

What is Metre bridge determine the unknown resistance by Metre bridge?

The Meter bridge is the modification of Wheatstone’s network used to determine the value of unknown resistance. The meter bridge consists of a thin, uniform, and homogenous conducting wire AC, rectangular wooden board between two thick L shaped metal strips C1 and C2 as shown in the diagram.

What is the use of Metre bridge?

A Meter bridge is used to calculate resistance values with high accuracy. They work on the principle of a balanced Wheatstone bridge.

What is Metre bridge what is it used for?

A meter bridge also called a slide wire bridge is an instrument that works on the principle of a Wheatstone bridge. A meter bridge is used in finding the unknown resistance of a conductor as that of in a Wheatstone bridge.

How are Wheatstone bridges measured?

The Wheatstone Bridge

1. I = V ÷ R = 12V ÷ (10Ω + 20Ω) = 0.4A.
2. VR2 = I × R2 = 0.4A × 20Ω = 8 volts.
3. VR4 = 0.4A × 10Ω = 4 volts.