Thevenins and Nortons Theorem

[rgarforth]

Hi all, Hope everyone is fine and dandy!

I am having real problems with my homework, it is based on thevenins and nortons theorem. please see the attached word document for the questions.
I understand on the first question that the circuit is divided into two before calculating the voltage and resitances. please can you provide explanations with diagrams on how this is done.

Any Help much appreciated! Thankyou!

 

[Mindscrape]

What is your question?

For the first problem you would find the thevenin equivalent between A and B, so that when you change the load resistance the characteristics of the load will be easier to calculate.

For the second problem you merely use the norton equivalent so that you have a current source, and can calculate the current through the load easily.

 

[m2003]

Dear student,

Thank you for reaching out for help with your homework on Thevenin's and Norton's Theorem. These two theorems are powerful tools that are commonly used in circuit analysis to simplify complex circuits and make them easier to analyze.

Thevenin's Theorem states that any linear circuit can be replaced by an equivalent circuit consisting of a voltage source in series with a resistance. This equivalent circuit is known as the Thevenin equivalent circuit. Similarly, Norton's Theorem states that any linear circuit can be replaced by an equivalent circuit consisting of a current source in parallel with a resistance, known as the Norton equivalent circuit.

To understand how to apply these theorems, let's take a look at a simple circuit with a voltage source and two resistors in series, as shown below:

[Insert diagram of circuit with voltage source and two resistors in series]

To find the Thevenin equivalent circuit, we will first remove the load resistor (RL) and find the open-circuit voltage (Voc) at the terminals A-B. This can be done by using the voltage divider rule, where Voc = V1 * (R2/(R1+R2)). In this case, V1 is the voltage across R1 and R2 is the total resistance of the circuit (R1+R2).

Next, we will find the Thevenin resistance (Rth) by short-circuiting the voltage source and finding the equivalent resistance between the terminals A-B. In this case, Rth = R1 + R2.

Now, we can construct the Thevenin equivalent circuit by placing the open-circuit voltage (Voc) in series with the Thevenin resistance (Rth), as shown below:

[Insert diagram of Thevenin equivalent circuit]

Similarly, to find the Norton equivalent circuit, we will first remove the load resistor (RL) and find the short-circuit current (Isc) at the terminals A-B. This can be done by using Ohm's law, where Isc = V1/R1. In this case, V1 is the voltage across R1 and R1 is the only resistance in the circuit when it is short-circuited.

Next, we will find the Norton resistance (Rn) by removing the voltage source and finding the equivalent resistance between the terminals A-B. In this case, Rn = R1.

Finally, we can construct the Norton equivalent circuit by