Question

In figure, the value of the source voltage is

• A. 12V
• B. 24V
• C. 30V
• D. 44 V

Answer 1

The correct option is C 30V


Method -1:

Using KCL,

$\frac{V_a-E}{6}+\frac{V_a}{6}-1=0$

$\Rightarrow 2V_a-E=6$ ... (i)

Where,

$\frac{E-V_a}{6}=2$

$\Rightarrow E-V_a=12$ ...(ii)

Solving equation (i) and (ii), we get

$V_a=18VandE=30V$

Method- 2:

$I=2+1=3A$

Apply KVL in second loop,

$E=2\times 6+3\times 6=30V$