The Open Door Web Site
HOME PAGE BIOLOGY CHEMISTRY PHYSICS ELECTRONICS HISTORY HISTORY of SCI & TECH MATH STUDIES LEARN FRENCH STUDY GUIDE PHOTO GALLERY
ATOMIC and NUCLEAR ELECTRICITY and MAGNETISM MEASUREMENTS MECHANICS OPTICS PRACTICAL WORK QUESTIONS RELATIVITY THERMAL PHYSICS WAVES
ELECTRICITY and MAGNETISM
Google
Custom Search
Electrical Power and Energy
Any electrical component which has some resistance will convert electrical potential energy to thermal energy, when current flows through.  
The rate at which energy is converted is easily calculated if we just remember the definitions of current and voltage.  
Consider the simple circuit shown below.  
 
   
The current, I, is a measure of the number of Coulombs of charge which pass through the resistor per second.  
   
The voltage, V, is a measure of the number of Joules of energy lost by each Coulomb of charge passing through the resistor.  
   
This tells us that the number of Joules of energy converted to thermal energy by the resistor per second (the power, P dissipated in the resistor) is simply given by  
 
From the definition of resistance we have  
 
Substituting for V or I in the power equation gives us two very useful expressions  
 
   
To calculate the quantity of energy converted to thermal energy, w, in t seconds we have  
 
SITE MAP
WHAT'S NEW
ABOUT
PRIVACY
COPYRIGHT
SPONSORSHIP
DONATIONS
ADVERTISING
 

© The Open Door Team
2016
Any questions or
problems regarding
this site should be
addressed to
the webmaster

David Hoult 2017

Hosted By
Web Hosting by HostCentric

 
SiteLock
 
 
Electricity and Magnetism Index Page