Ohm’s Law
Series:
Parallel:
RT = R 1 + R 2 + R 3
VT = V1 + V2 + V3
PT = P1 + P2 + P3
IT = I1 = I2 = I3
1 1 1 1
=
+ +
RT R1 R2 R3
VT = V1 = V2 = V3
PT = P1 + P2 + P3
IT = I1 + I2 + I3
R1
R2
R3
Prefixes :
1 KOhm = 1,000 Ohm 1 MOhm = 1,000,000
1 A = 1,000 mA
1 W = 1,000 mW
Always make your calculations without the prefix.
R1
R2
R3
Find RT if R1 = 5 Ohm R2 = 10 Ohm R3 = 20 Ohm R4 = 30 Ohm