<img src="https://d5nxst8fruw4z.cloudfront.net/atrk.gif?account=iA1Pi1a8Dy00ym" style="display:none" height="1" width="1" alt="" />
Dismiss
Skip Navigation
Our Terms of Use (click here to view) have changed. By continuing to use this site, you are agreeing to our new Terms of Use.
You are viewing an older version of this Concept. Go to the latest version.

Ohm's Law

When electricity passes through a resistor it loses voltage and releases power.

Atoms Practice
Estimated8 minsto complete
%
Progress
Practice Ohm's Law
Practice
Progress
Estimated8 minsto complete
%
Practice Now
Turn In
Batteries

Batteries

Credit: Anton Fomkin
Source: http://www.flickr.com/photos/antonfomkin/3046849320/
License: CC BY-NC 3.0

Creating electrical energy via stored chemical energy, batteries are able to power the millions of devices that surround us every day.

News You Can Use

  • A battery is a group of chemical cells where each cell consists of two metal plates, or electrodes, that are immersed in a conducting fluid. Due to a chemical reaction between the plates and the fluid, one of the plates becomes more positively charged than the other. Usually considered as ideal batteries, ideal batteries are a source of an electromotive force (emf) that is able to maintain a constant potential difference between the two terminals.
  • All real batteries have an internal resistance, meaning the potential difference between the terminals is not the same as the electromotive force of the battery. In a real battery, there exists an internal resistance of the battery given by r. By creating a circuit diagram of a battery, it is easy to see that the voltage across the terminal in a real battery is given as:

VaVb=εIr

Explore More

Using the information provided above, answer the following questions.

  1. A 9 Ω resistor is connected across a battery of emf 5 V and internal resistance of 1 Ω. What is the current?
  2. If the emf of the battery is doubled, what would the current be in the previous problem?
  3. Is the terminal voltage greater or less than the emf of the battery?

Notes/Highlights Having trouble? Report an issue.

Color Highlighted Text Notes
Please to create your own Highlights / Notes
Show More

Image Attributions

  1. [1]^ Credit: Anton Fomkin; Source: http://www.flickr.com/photos/antonfomkin/3046849320/; License: CC BY-NC 3.0

Explore More

Sign in to explore more, including practice questions and solutions for Electric Current.
Please wait...
Please wait...