Question

For the circuit shown in the figure, Thevenin's voltage and Thevenin's equivalent resistance at terminals a-b is

• A. 5 V and 2 $\Omega$
• B. 7.5 V and 2.5 $\Omega$
• C. 4 V and 2 $\Omega$
• D. 3 V and 2.5 $\Omega$

Answer 1

The correct option is B 7.5 V and 2.5 $\Omega$

For V${}_{Th}$ :

$\frac{V_{ab}}{5}+\frac{V_{ab}-10}{5}=1$

(when current source is in series with voltage source effect of current source is taken.)

2V${}_{ab}$ = 15 $\Rightarrow$ V${}_{ab}$ = 7.5

$\frac{0.5I_1}{I_1}=\frac{5}{R}\Rightarrow$ 10$\Omega$

(impendance connected to $0.5I_1$ current source)

For R${}_{Th}$, Make independent sources dead,


R${}_{Th}$ = 5 || 5 = 2.5$\Omega$