Question
Explain the principle of Wheatstone bridge for determining an unknown resistance.
Solution
Wheatstone bridge principle states that if four resistances P, Q, R and S are arranged to form a bridge as shown in the fig. below with a cell E and one way key, put between the points A and C and a galvanometer is connected in between the points B and D such that there is no current through G. The balance point is obtained when, galvanometer shows no deflection.
In this case,
It is usually used to find the value of an unknown resistance.
