Ohms law

(Potential Difference ) Variables Name Variable S.I. Unit Voltage (Potential Difference ) V volts (V) Current I amperes (A) Resistance R ohms (W)

http://phet.colorado.edu/en/simulation/ohms-law

YOU YOU V=IR + - Ohm’s Law What determines the voltage of a circuit? What determines the resistance of a circuit? YOU + -

A better way to think of Ohm’s Law V I = R + -

A better way to think of Ohm’s Law V I = R + -

A better way to think of Ohm’s Law V = R + -

GFCI

Circuit Breaker How prevent overload? a device that automatically interrupts the circuit if the current exceeds a certain value or changes quickly. Circuit Breaker

Fuse Box

Car Fuses

Fuse How prevent overload? A safety device consisting of a length of wire which melts when the current exceeds a certain value. This breaks the circuit. Fuse