Question

Using kirchhoff's laws, calculate the potential difference across the 8 ohm resistor.

Answer 1

Dear Student,

You posted an incomplete question, perfect answer to which is rather impossible. But I will explain here about Kirchhoff's law which you can apply to any electrical circuit to get the answer.

# Solution-

In balanced Wheatstone's bridge, zero current flow through galvanometer. Means while applying Kirchoff's law we can neglet this path.

Look at the figure,

No current flows through galvanometer G if circuit is balanced.

Applying Kirchoff's law to

(1) Mesh ABDA,

-I1R1 + (I-I1)R4 = 0

I1R1 = (I-I1)R4 ….(1)

(2) Mesh BCDB,

-I1R2 + (I-I1)R3 = 0

I1R2 = (I-I1)R3 ….(2)

Dividing (1) by (2),

I1R1 / I1R2 = (I-I1)R4 / (I-I1)R3

R1/R2 = R4/R3

This is balancing condition for Wheatstone's bridge.

Best luck for exams buddy...