Question

In the given circuit, find I if the potentials at A and B are equal

(1) 1A

(2) 2A

(3) 3A

(4) 4A

Answer 1

Correct option is : (2) 2A

Given potential at A and B are equal.

\(\Rightarrow \) This is a wheat-stone Bridge

\(i.e., \ \frac{R}{10 \Omega} = \frac{40 \Omega }{20 \Omega}\)

or = \(R = 20\Omega \) 

Equivalent resistance = \(20\Omega \)

\(I = \frac{40 V}{20 \Omega} = 2A\)