Notes

Wheatstone Bridge …

Wheatstone Bridge is:
To measure a resistance more accurately Kristie devised and Wheatstone popularized a special network design called Wheatstone Bridge. It is an arrangement of four resistances that can be used measure one of them in terms of the rest. In the given figure-
(1) S is a unknown resistance to be measured. Arm CD of the bridge is called unknown arm.
(2) P and Q are two adjustable resistances connects in two ratio arms AB and BC of the bridge.
(3) R is the adjustable known resistance. Arm AD is called known arm.
(4) A sensitive galvanometer G is connected in one of the cross arm BD of the bridge.
(5) A battery E along with a key K is connected in other cross arm AC. Arm AC and BD are called Conjugate Arms.