Does a flashlight battery have internal resistance?

[carnivalcougar]

Homework Statement

Does a flashlight battery have internal resistance? Explain.

Homework Equations

V = ε - Ir

The Attempt at a Solution

Yes, they do have internal resistance. This results in the open circuit ε being different than the voltage measured across the terminals if a current is drawn from the source.

I'm not sure why, though. I'm also not sure if the question is asking why they have internal resistance or if its just asking what the implications of this internal resistance are.

 

[berkeman]

Homework Statement

Does a flashlight battery have internal resistance? Explain.

Homework Equations

V = ε - Ir

The Attempt at a Solution

Yes, they do have internal resistance. This results in the open circuit ε being different than the voltage measured across the terminals if a current is drawn from the source.

I'm not sure why, though. I'm also not sure if the question is asking why they have internal resistance or if its just asking what the implications of this internal resistance are.

Yes, all real-life batteries and power supplies have internal series resistance. You can Google battery chemistry internal resistance to learn more to help you answer that part of the question.

 

[CWatters]

What he said.

Just about everything has resistance (except superconductors), including the terminals of the battery.

 

[rcgldr]

Although the term is internal resistance, part of this so called "resistance" is due to electro chemical factors, which reduce voltage output as current increases. Wiki article:

http://en.wikipedia.org/wiki/Internal_resistance#Batteries

 

[HalfLostAndSearching]

The reason why flashlight batteries have internal resistance is due to the nature of their construction. Inside the battery, there are layers of chemicals and materials that work together to produce the necessary electrical energy. As the battery is used and discharged, these materials start to break down and lose their effectiveness, resulting in an increase in internal resistance.

The implications of this internal resistance are that it affects the overall performance of the battery. As the internal resistance increases, it becomes more difficult for the battery to deliver the required amount of current to power the flashlight. This can result in a decrease in the brightness of the flashlight or a shorter battery life.

Additionally, the internal resistance can also cause a voltage drop across the battery when a load is applied. This means that the voltage measured across the battery terminals will be lower than the open circuit voltage. This can affect the accuracy of voltage measurements and can also cause issues in electronic devices that require a constant and stable voltage.

In summary, yes, flashlight batteries do have internal resistance, which can have implications on their performance and the devices they power.