Question

Calculate the steadystate current in the $2\,\Omega$ resistor shown in the circuit in the figure.

The internal resistance of the battery is negligible and the capacitance of the condenser $C$ is $0.2\, \mu F$.

• A. $0.6\,A$
• B. $0.9\,A$
• C. $1.2\,A$
• D. $0.1\,A$

Answer 1

Answer: (B)

At steady state, no current flows through the capacitor branch of the circuit.

$2\,\Omega$ and $3\,\Omega$ are in parallel. Let their combined resistance be $R$.
$\therefore R=\frac{2 \times 3}{2+3}=\frac{2\times3}{5}$
$=1.2\,\Omega$
Net current supplied $=\frac{6}{1.2+2.8}$
$I=1.5\,A$
$I$ divides into $I_{1}$ and $I_{2}$
$2I_{1}=3I_{2}\quad$ [Potential Difference is same]
or $I_2=2I_1/3$
$I_{1}+I_{2}=1.5$ or $I_{1}+\frac{2I_{1}}{3}$
$=1.5$
or $\frac{5I_{1}}{3}=1.5$ or $I_{1}=\frac{1.5 \times 3}{5}\,A$
$=0.9\,A$