Circuit Notes:
Series Circuits 1. Fill all of the R values into the chart. R1 = 10 ohms S V I R R1 10 R2 20 R3 30 T Vt = 30V R2 = 20 ohms R3 = 30 ohms
Series Circuits S V I R 10 20 30 T .5 60 Calculate Rt Plug in Vt 4. Calculate It R1 = 10 ohms S V I R R1 10 R2 20 R3 30 T .5 60 Vt = 30V R2 = 20 ohms R3 = 30 ohms
Series Circuits In series circuits, I’s are all equal. Plug in I’s Calculate Voltage Drops Check to make sure they add up to Vt! R1 = 10 ohms Vt = 30V R2 = 20 ohms S V I R R1 5 .5 10 R2 20 R3 15 30 T 60 R3 = 30 ohms
Parallel Circuits P V I R 20 30 60 T 10 Fill in R’s Vt = 30V R1 = 10 ohms R2 = 30 ohms R3 = 60 ohms Fill in R’s 2. Calculate Rt remember to calculate the reciprocals!
Parallel Circuits 1/Rt = 1/R1 + 1/R2 + 1/R3 1/Rt = 1/20 + 1/30 + 1/60 Rt = 60/6 = 10 ohms!
Parallel Circuits P V I R 20 30 60 T 3 10 Plug in Vt Vt = 30V R1 = 20 ohms R2 = 30 ohms R3 = 60 ohms Plug in Vt 4. Calculate It (ohm’s Law!)
Parallel Circuits P V I R 30 1.5 20 1 .5 60 T 3 10 Vt = 30V R1 = 20 ohms R2 = 30 ohms R3 = 60 ohms In a parallel circuit, all V’s are equal! Fill in V’s. Calculate I’s Check to make sure they add up to It!
Combination Circuits P V I R 20 10 Find the resistor farthest from the power source. Determine if it is Parallel or series. If it is parallel: Set up a parallel box. Calculate Rp (remember reciprocals!) R1 = 10 ohms Vt = 120V R2 = 20 ohms R3 = 20 ohms P V I R R3 20 R2 Rp 10 R4 = 40 ohms
Combination Circuits S V I R 10 40 T 60 P V I R 20 10 Find series resistiors. Set up Series box. 5. Calculate Rt. R1 = 10 ohms S V I R R1 10 Rp R4 40 T 60 Vt = 120V R2 = 20 ohms R3 = 20 ohms R4 = 40 ohms P V I R R3 20 R2 Rp 10 Effective Circuit: Parallel resistors combined act as a single series resistor
Combination Circuits S V I R 20 2 10 80 40 T 120 60 P V I R 20 10 Rp R4 80 40 T 120 60 R1 = 10 ohms Vt = 120V R2 = 20 ohms R3 = 20 ohms Plug in Vt. Calculate It Series I’s are the same! 8. Plug in I’s 9. Calculate V’s R4 = 40 ohms P V I R R3 20 R2 Rp 10
Combination Circuits S V I R 20 2 10 80 40 T 120 60 P V I R 20 1 2 10 Rp R4 80 40 T 120 60 R1 = 10 ohms R2 = 20 ohms R3 = 20 ohms R4 = 40 ohms Substitute the Rp row into the Parallel box. V’s are equal in a parallel circuit. Plug in V’s Calculate I’s Your done! P V I R R3 20 1 R2 Rp 2 10