Thevenin voltage and resistance

In summary, to calculate the Thevenin voltage and resistance, we can use the equations V=(Vt*R)/(Rt+R) and I=Vt/(Rt+R). To find Vt, we need to solve for Rt first. We can do this by finding the open circuit voltage across the terminals a and b. To find Rt, we can calculate the current that would flow if we short circuit the output and then divide Vt by this current. Alternatively, we can look into the terminals and replace the battery with a short circuit to find the Thevenin resistance.
  • #1
yoamocuy
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0

Homework Statement


Calculate the Thevenin voltage Vt and the Thevenin resistance Rt.



Homework Equations


V=(Vt*R)/(Rt+R)

I=Vt/(Rt+R)


The Attempt at a Solution


I'm thinkin that my R is 1 ohm but I can't figure out how to simply the rest of the resistors to get Rt. If I can get Rt, then I can solve for Vt. Is my thinking correct or am I completely off? I've attached a picture of the diagram. Any input would be great, thanx.
 

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  • #2
The resistor across the battery is not part of the problem. Someone's little joke.

To get the Thevenin voltage, work out the open circuit voltage across the terminals a and b.

To get the Thevenin resistance, calculate the current that would flow if you short circuited the output. Then divide the Thevenin voltage by this current to get the Thevenin resistance.

Alternatively, you can "look" into the terminals and replace the battery with a short circuit. The resistance you "see" when you do this is the Thevenin resistance.
 
  • #3


Your thinking is on the right track. In order to find the Thevenin voltage and resistance, you need to simplify the circuit by combining resistors in series and parallel. Once you have simplified the circuit, you can use the equations V=(Vt*R)/(Rt+R) and I=Vt/(Rt+R) to solve for Vt and Rt.

In this case, you are correct that the total resistance (R) is 1 ohm. However, to find Rt, you will need to combine the 4 ohm and 6 ohm resistors in series to get a total resistance of 10 ohms. Then, you can combine this 10 ohm resistor in parallel with the 10 ohm resistor to get a total resistance of 5 ohms. This is your Rt.

Now, you can use the equation V=(Vt*R)/(Rt+R) to solve for Vt. Plugging in V=12 volts, R=1 ohm, and Rt=5 ohms, you should get Vt=10 volts.

Therefore, the Thevenin voltage is 10 volts and the Thevenin resistance is 5 ohms.
 

1. What is Thevenin voltage and resistance?

Thevenin voltage and resistance are two important concepts in electrical engineering and circuit analysis. Thevenin voltage is the voltage that would be measured across two terminals of a circuit if all the circuit components were replaced by a single voltage source. Thevenin resistance is the equivalent resistance of the circuit seen from those two terminals.

2. How is Thevenin voltage and resistance calculated?

Thevenin voltage is calculated by finding the open-circuit voltage across the terminals of the circuit. Thevenin resistance is calculated by finding the equivalent resistance of the circuit when all voltage sources are replaced by short circuits and all current sources are replaced by open circuits.

3. Why is Thevenin voltage and resistance important?

Thevenin voltage and resistance allow for simplification of complex circuits, making them easier to analyze and design. They also help in finding the maximum power transfer in a circuit and determining the effects of different loads on the circuit.

4. What is the difference between Thevenin voltage and Norton voltage?

Thevenin voltage is the voltage across two terminals of a circuit when all components are replaced by a single voltage source, while Norton voltage is the current through a short circuit between those two terminals when all components are replaced by a single current source. Thevenin resistance is calculated using open-circuit voltage, while Norton resistance is calculated using short-circuit current.

5. How is Thevenin voltage and resistance used in circuit analysis?

Thevenin voltage and resistance are used in circuit analysis to simplify complex circuits into a single voltage source and resistance, making it easier to analyze and design the circuit. They are also used to determine the maximum power transfer in a circuit and to find the effects of different loads on the circuit.

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