Question

Consider the following figure:


The current $I_s$ in Amps in the voltage source, and voltage $V_s$ in volts across the current source respectively, are

• A. 13, -20
• B. 8, -10
• C. -8, 20
• D. -13, 20

Answer 1

The correct option is D -13, 20


Voltage across 1 $\Omega$ resistance,
$V_1$ = 10 V
Current through 1 $\Omega$ resistance,
$I_1=\frac{10}{1}=10Amp.$
Voltave across 2 $\Omega$ resistance,
$V_2$ = 10 V
Current through 2 $\Omega$ resistance,
$I_2=\frac{10}{2}=5Amp.$
Apply KCL at node A,

$-2+I_s+I_2+I_1=0$

$I_s=2-I_1-I_2=2-10-5$

$I_s=-13Amp$
Voltage at node A,

$V_A=10V$

$V_s-10=10V$

$V_s=10+10=20V$

$V_s=20V$