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NUE 052 - Resistance, Ohms Law & Power Dissipation

Resistance is the opposition to current flow in a conductor, measured in Ohms. The symbol is R.
A good conductor such as copper has a low resistance. A good insulator such as mica has a high resistance.
Ohms law is named after Georg Simon Ohm who presented his laws back in 1827. In his honour the unit of electrical resistance was named the 'ohm' . Ohms law relates voltage, current and resistance.
Power is the rate that energy is used or dissipated, measured in Watts. The symbol is P.
Use Ohms law to find a value - cover ONE symbol in the triangle to solve the formula
Volts (V), Amps (I) & Ohms (R) Watts (P), Volts (V) & Amps (I)
     
 
Terms used with voltage, current and resistance

 Quantity

 Abbreviation

 Measurement

 Symbol

 EMF

 E

 volt

 V

 voltage

 V

 volt

 V

 current

 I

 ampere

 A

 resistance

 R

 ohm

 
 You can download an Ohms law calculator here for a bit of fun (204 kb download)
Practice Tests Practice tests are available on the Practice Test page

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