Q. 1.P.39

Find the Thevenin equivalent voltage and resistance for the following circuit. Also determine load current and voltage.

Verified Solution

For determining $V_{ Th }$,

Step 1: Open 5 kΩ load to obtain the following circuit

Step 2: Calculate the open circuit voltage across AB, which is obtained as $V_{ Th }=12 V$.
For determining $R_{ Th }$,

Step 1: Make all active sources equal to zero.

$R_{ Th }=12 k \Omega|| 4 k \Omega \text { in series with } 8 k \Omega=11 k \Omega$

Now, by the Thevenin theorem, new circuit looks as follows:

So, $I_{ L }=\frac{V_{ Th }}{R_{ Th }+R_{ L }}=\frac{12}{11+5}=0.75 mA$

$V_{ L }=I_{ L } \times R_{ L }=0.75 mA \times 5 k \Omega=3.75 V$