Prelab Brief
To determine the unknown resistance X using a Meter Bridge based on the Wheatstone bridge principle, and to verify the formula X = R(100 − l)/l.
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Theory
Determine unknown resistance using the Wheatstone bridge principle and find the null point on a 1-metre uniform wire. To determine the unknown resistance X using a Meter Bridge based on the Wheatstone bridge principle, and to verify the formula X = R(100 − l)/l.
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Formula
X = R(100 − l)/l
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Aim
To determine the unknown resistance X using a Meter Bridge based on the Wheatstone bridge principle, and to verify the formula X = R(100 − l)/l.
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Apparatus
- Meter bridge wire (1 m uniform resistance wire)
- Resistance box (known resistance R)
- Unknown resistance X
- Galvanometer
- Jockey
- Battery / EMF source
- Connecting wires and key
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Procedure
- Connect the known resistance R in the left gap and unknown resistance X in the right gap of the meter bridge.
- Connect the battery across the ends A and B, and the galvanometer between the midpoint D and the jockey J.
- Slide the jockey along the wire and press lightly at various points.
- Find the position where the galvanometer shows zero deflection (null point).
- Record the balancing length l (from end A).
- Calculate X using X = R × (100 − l) / l.
- Repeat with different values of R and take the mean of X.
Pre-Lab Questions
What is the main aim of the Meter Bridge Experiment?
Which principle is demonstrated in the Meter Bridge Experiment?
What apparatus is required for this experiment?
Why is Meter bridge wire (1 m uniform resistance wire) used in this experiment?
What formula or relationship is verified in this experiment?
What precaution should be followed while performing this experiment?
What conclusion can be drawn from the Meter Bridge Experiment?