Home  www.playhookey.com  Thu, 04152021 

Direct Current

Alternating Current

Semiconductors

Digital

Logic Families

Digital Experiments

Computers

 Analog  Analog Experiments  Oscillators  Optics  HTML Test  

 Fundamentals of Electricity  Resistors  Capacitors  Inductors and Transformers  Combinations of Components   

The Resistor

The Color Code

Color Code Practice

Resistors in Series

Resistors in Parallel

Voltage Dividers

Resistance Ratio Calculator

 ThreeTerminal Configurations  Delta <==> Wye Conversions  The Wheatstone Bridge  Applications of the Wheatstone Bridge  
Resistors in Parallel 

When two resistors are connected in parallel, as shown to the right, the same voltage appears across each resistor. However, each resistor provides its own path for the flow of current. If the resistors have different resistance values, they will carry different amounts of current, each in accordance with Ohm's Law.
As a result, we can calculate the currents through each resistor, and the total current I, as:
I_{1} = E ÷ R_{1}
I_{2} = E ÷ R_{2}
I = I_{1} + I_{2}
Now let's apply Ohm's Law again, and solve the above equation for total resistance:
E  =_{ }  E  +_{ }  E 
R_{T}  R_{1}  R_{2} 
Since E is the same everywhere in the circuit, we can multiply both sides of the equation by 1/E and thus remove it. Then we solve for R_{T}, the total circuit resistance:
1  =_{ }  1  +_{ }  1 
R_{T}  R_{1}  R_{2}  
R_{T} =  1  
1  +  1  
R_{1}  R_{2}  
R_{T} =  1  
R_{2}  +  R_{1}  
R_{1}R_{2}  R_{2}R_{1}  
R_{T} =  1  
R_{1} + R_{2}  
R_{1} × R_{2}  
R_{T} =  R_{1} × R_{2}  
R_{1} + R_{2} 


 
All pages on www.playhookey.com copyright © 1996, 20002015 by
Ken Bigelow Please address queries and suggestions to: webmaster@playhookey.com 