Finding the battery voltages in this circuit

In summary, the conversation discusses a circuit and the values of ε1 and ε3. The attempt at a solution involves using Kirchhoff's second law and arriving at a different answer than the one given in the textbook. The person concludes that the book is wrong and suggests that the charge from a to b may not be 3A. However, this is not possible as it would result in an impossible current flow.
  • #1
Eitan Levy
259
11

Homework Statement


This circuit is given:[/B]
upload_2017-12-16_22-10-55.png

What are the values of ε1 and ε3?

Homework Equations


IR=V

The Attempt at a Solution


I get the right answer for ε1 (3V).
But I get that ε3=12V and not 15 (the answer in the textbook).
First the charge from a to b is 3A.
Then I simply use Kirchhoff's second law, which gives: 2Iab-6+10+2-ε3=0.
That gives ε3=12.
Am I wrong or the book? Maybe the charge from a to b is not 3A?
 

Attachments

  • upload_2017-12-16_22-10-55.png
    upload_2017-12-16_22-10-55.png
    26.5 KB · Views: 732
Physics news on Phys.org
  • #2
Eitan Levy said:
Am I wrong or the book?
book is wrong
Maybe the charge from a to b is not 3A?
How could that POSSIBLY be true? If it were, then the currents into/out of node b would not add up to zero. A miracle.
 

1. How do you calculate the battery voltages in a circuit?

To calculate the battery voltages in a circuit, you need to use the formula V=IR, where V is voltage, I is current, and R is resistance. You will need to measure the current and resistance at each point in the circuit, and then use the formula to calculate the voltage.

2. What tools are needed to find the battery voltages in a circuit?

To find the battery voltages in a circuit, you will need a multimeter, which can measure both current and resistance. You may also need a circuit diagram of the circuit in order to identify the different points at which you need to measure the current and resistance.

3. Can you find the battery voltages without using a multimeter?

No, a multimeter is necessary to accurately measure the current and resistance in a circuit. Trying to estimate these values without a multimeter can result in inaccurate calculations and potentially damage the circuit.

4. What is the importance of finding the battery voltages in a circuit?

Finding the battery voltages in a circuit is important because it allows you to understand the functioning of the circuit and identify any potential issues. It also helps in troubleshooting and making any necessary adjustments to improve the performance of the circuit.

5. What factors can affect the battery voltages in a circuit?

The battery voltages in a circuit can be affected by factors such as the type and quality of the battery, the amount of current being drawn from the circuit, and any resistance present in the circuit. Temperature and other external factors can also impact the battery voltages.

Similar threads

  • Introductory Physics Homework Help
Replies
5
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
475
  • Introductory Physics Homework Help
Replies
7
Views
4K
  • Introductory Physics Homework Help
Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
16
Views
504
  • Introductory Physics Homework Help
Replies
4
Views
182
  • Introductory Physics Homework Help
Replies
1
Views
3K
  • Introductory Physics Homework Help
Replies
6
Views
666
  • Introductory Physics Homework Help
Replies
9
Views
8K
Replies
3
Views
236
Back
Top