Question

In the circuit shown, the current in the $1\Omega$ resistor is:

• A. $0.13A$, from$P$ to $Q$
• B. $1.3A$, from $P$ to $Q$
• C. $0A$
• D. $0.13A$, from $Q$ to $P$

Answer 1

Answer: (D)

Applying Kirchoff's law where connected port $PQ$ to ground . Consider the grounded circuit as shown in the figure 2

Applying Kirchoff's law at point Q. Incoming current at Q outgoing current from Q

$\frac{V+6}{3}+\frac{V}{1}=\frac{9-V}{5}V(\frac{1}{3}+\frac{1}{5}+1)=\frac{9}{5}-2V\left(\frac{5+3+15}{15}\right)=\frac{9-10}{5}V\left(\frac{23}{15}\right)=-\frac{1}{5}V=-(-\frac{3}{25})=-0.13V$

Curent in the $1\Omega$ resistance in $0.13A$ from Q to P.