Experiment · Experimental skills

Metre Bridge Experiment

Find an unknown resistance with a virtual metre bridge: slide the jockey to the null point and calculate X.

Last updated: 26 October 2026

Direct answer

Find an unknown resistance with a virtual metre bridge: slide the jockey to the null point and calculate X.

The unknown resistance X is different every visit. Find the null point, then record readings for 3–4 values of R and average X.

Simulation

Experimental skills

Known resistance R (Ω) 10 Ω

Jockey position (cm) 50 cm

Record readings in the Notebook tab below.

What's happening? The unknown resistance X is different every visit. Find the null point, then record readings for 3–4 values of R and average X.

Learn more

Where it is in NCERT: Class 12 Physics Part I, “Current Electricity” (Wheatstone Bridge, Metre Bridge, Kirchhoff's Rules, Resistivity of Various Materials); Class 11 Physics Part I, “Units and Measurement” (Significant Figures, Errors in Measurement, Accuracy and Precision of Measuring Instruments, Dimensions of Physical Quantities) · ncert.nic.in
Topic notes and formulas: Experimental Skills (Physics Practicals)
Printable formula sheet

Full lecture: INSTRUMENTS & OPTICAL INSTRUMENT in 1 Shot: All Concepts & PYQs Covered || JEE Main & Advanced — JEE Wallah
Other trusted simulations: Pendulum Lab (PhET, University of Colorado) · Circuit Construction Kit: DC - Virtual Lab (PhET, University of Colorado)

FAQs

Why should the null point be near the middle of the wire?

End errors and the percentage error in l are smallest there, so X is most accurate.

What is the formula for a metre bridge?

X/R = l/(100 − l), where l is the balancing length on the X side.