Current Electricity
Class 12 · Current Electricity
Wheatstone Bridge
Balance condition P/Q = R/S. Galvanometer reads zero when balanced.
Key Notes
01
Four resistors in diamond configuration with battery and galvanometer.
02
Balance condition: P/Q = R/S — galvanometer reads zero, no current through bridge.
03
Used to measure unknown resistance precisely.
Formulas
Balance
At balance, V across galv = 0.
Important Points
Strain gauges, temperature sensors all use Wheatstone bridges.
Sensitivity is highest when all four arms are comparable in resistance.
Wheatstone Bridge notes from sciphylab (also known as SciPhy, SciPhy Lab, SciPhy Labs, Physics Lab). Class 12 physics revision for JEE Mains, JEE Advanced, NEET UG, AP Physics 1/2/C, SAT, and CUET-UG.