How do I know what the internal resistance of a battery is in a diagram?

In summary, to find the terminal voltage of the batteries in the circuit, you can use the equation V = IR. The solution manual states that the voltage is equal to the battery voltage minus the voltage drawn from the resistance. It is convention to label a resistor with "r" beside a battery as its internal resistance.
  • #1
chiddler
37
0

Homework Statement


I am trying to find terminal voltage of the batteries in the circuit shown.

Homework Equations



V = IR

The Attempt at a Solution



The solution manual says that it's the battery voltage, v, minus the voltage drawn from the resistance v = I * R. I understand this.

I do not understand how I'm supposed to know that the 1 ohm resistor adjacent to each battery corresponds to the battery's internal resistance. I would very much appreciate help with this. Thank you!
 

Attachments

  • schematic.png
    schematic.png
    3.7 KB · Views: 377
Physics news on Phys.org
  • #2
It's labeled with "r". There's no rhyme or reason to this; it's just convention that whenever you see a resistor labeled "r" beside a battery, you should assume that it's internal resistance.
 

1. How do I determine the internal resistance of a battery from a diagram?

To determine the internal resistance of a battery from a diagram, you will need to know the battery's voltage and current. Once you have this information, you can use Ohm's Law (V=IR) to calculate the internal resistance. Simply divide the voltage by the current to get the internal resistance.

2. Where can I find the voltage and current information for a battery in a diagram?

The voltage and current information for a battery can usually be found on the battery itself or in the accompanying documentation. In a diagram, the voltage is typically represented by the symbol "V" and the current by the symbol "I".

3. Can the internal resistance of a battery change over time?

Yes, the internal resistance of a battery can change over time. Factors such as age, usage, and temperature can all affect the internal resistance of a battery. It is important to regularly check the internal resistance of a battery to ensure it is functioning properly.

4. What is a typical internal resistance for a battery?

The internal resistance of a battery can vary depending on the type and size of the battery. However, a typical internal resistance for a standard AA battery is around 0.1-0.3 ohms.

5. Can I measure the internal resistance of a battery without a diagram?

Yes, it is possible to measure the internal resistance of a battery without a diagram. You will need a multimeter to measure the voltage and current of the battery. Once you have this information, you can use Ohm's Law to calculate the internal resistance as described in the first question.

Similar threads

How to solve for EMF and internal resistance in a circuit?
    • Introductory Physics Homework Help
Replies
8
Views
1K
Circuit with potential difference across battery being zero?
    • Introductory Physics Homework Help
Replies
3
Views
237
Why do the headlights on the car become dim when the car is starting?
    • Introductory Physics Homework Help
Replies
4
Views
256
Batteries in series, parallel, and internal resistance
    • Introductory Physics Homework Help
Replies
24
Views
4K
Internal Resistance of a Car Battery
    • Introductory Physics Homework Help
Replies
8
Views
12K
Finding the internal resistance of battery
    • Introductory Physics Homework Help
Replies
10
Views
3K
Unraveling the Mystery of EMF Internal Resistance
    • Introductory Physics Homework Help
Replies
2
Views
1K
Calculating current with and without internal resistance
    • Introductory Physics Homework Help
Replies
6
Views
2K
Insights How to Measure Internal Resistance of a Battery
    • Electromagnetism
Replies
12
Views
3K
Optimum Battery (and Wire) to Power 10x Mini 1.5V Bulbs in Parallel?
    • Introductory Physics Homework Help
Replies
6
Views
753

Hot Threads

Recent Insights

Back
Top