Ohm’s Law /Power 

Ohm’s Law                             :    V = I R        

•  V electric potential difference in  V     
•  I   electric current in A   
•  R  electric resistance in  Ω

Power      :    P = V I       

• P  power in W

Example

An electric kettle has a power of  2.0 x 10³  W . The voltage is  2.3 x 10² V

Calculate the electric resistance of the heating element.

P = V I

2.0 x 10³ = (2.3 x 10²)(I)

I = (2.0 x 10³)/(2.3 x 10²) = 8.70 A

V = I R

2.3 x 10² = 8.70 x R

R = 26.4 Ω = 2.6 x 10¹  Ω