Ohm's law

PROOF OF OHM'S LAW

V=mI+c  (where m is the gradient)

Because             the line of equation passes through origin(0,0)

so                                 c=0   

                            

                                   V=mI

                      (where the gradient m is resistance, R)

We proved that current (I)  is directly proportional to voltage (V), therefore ohm's law works~

Ohm's law (apply to both AC and DC circuit)

The current through a conductor is proportional to the potential difference across it under constant physical conditions.

Find voltage

If the current (I) is 0.2 amps and resistance (R) is 180 ohms, then

V = 0.2A x 180 Ω = 36V

Find current

If the voltage (v) is 110v and resistance is 22000 ohms, then

I = 110V / 22000 Ω = 0.005A

Find resisitance

If the voltage (V) is 230v and the current is 5 amps, then

R = 230V / 5A = 46 Ω

                                                                   南极熊NJX