Question

The current $I_1$ (in $A$ ) flowing through the $1\Omega$ resistor in the given circuit is

• A. $0.2$
• B. $0.4$
• C. $0.5$
• D. $0.25$

Answer 1

Answer: (A)

Given circuit is

In given circuit $V_{AB}=1V,$ so upper branch of circuit is as shown below figure

Equivalent resistance of upper branch,
$R_{eq}=\left(1\Omega \parallel 1\Omega \right)+2\Omega$
$=\frac{1}{2}+2=\frac{5}{2}\Omega$
So, current in upper branch.
$I=\frac{V}{R}=\frac{V_{AB}}{R_{eq}}=\frac{1}{5/2}=\frac{2}{5}A$
At point $C$ , this current is equally divided into two parts. So,
$I_1=\frac{1}{2}\left(\frac{2}{5}\right)=0.2A$