How do you perform practical of meter bridge?

To measure an unknown resistance using a meter bridge.

Materials:

* Meter bridge

* Battery

* Jockey

* Rheostat

* Connecting wires

* Unknown resistor

Procedure:

1. Set up the meter bridge as shown in the diagram. The jockey should be in contact with the left-hand end of the bridge wire.

2. Connect the battery to the terminals marked "B" and "C".

3. Adjust the rheostat until the galvanometer reads zero. This indicates that the bridge is balanced.

4. Measure the length of the bridge wire from the left-hand end to the jockey. This is called the "balancing length".

5. Calculate the unknown resistance using the formula:

```

R = R<sub>k</sub> * (l<sub>1</sub>/l<sub>2</sub>)

```

where:

* R is the unknown resistance

* R_k is a known resistance

* l₁ is the balancing length

* l₂ is the total length of the bridge wire

Example:

If the known resistance is 10 ohms, the balancing length is 50 cm, and the total length of the bridge wire is 100 cm, then the unknown resistance is:

```

R = 10 ohms * (50 cm/100 cm) = 5 ohms

```

Conclusion:

The unknown resistance is 5 ohms.