- Calculate the equivalent resistance of R3, R4, and R5 in series: R345 = R3 + R4 + R5 = 330 Ω + 220 Ω + 270 Ω = 820 Ω.
- Combine R345 with R2 in parallel: 1/R2345 = 1/R2 + 1/R345 = 1/820 Ω + 1/820 Ω = 2/820 Ω, so R2345 = 410 Ω.
- Add R1 and R6 in series with R2345: R_total = R1 + R2345 + R6 = 390 Ω + 410 Ω + 1200 Ω = 2000 Ω.
- Use Ohm’s Law to find total current: I_total = V_T / R_total = 50 V / 2000 Ω = 0.025 A or 25 mA.
- Calculate the equivalent resistance of R7, R8, and R9 in series: R789 = R7 + R8 + R9 = 12 Ω + 18 Ω + 10 Ω = 40 Ω.
- Combine R789 with R5 in parallel: 1/R5789 = 1/R5 + 1/R789 = 1/120 Ω + 1/40 Ω = (1 + 3)/120 Ω = 4/120 Ω, so R5789 = 30 Ω.
- Combine R5789 with R4 and R6 in series: R456789 = R4 + R5789 + R6 = 100 Ω + 30 Ω + 270 Ω = 400 Ω.
- Combine R456789 with R2 in parallel: 1/R2456789 = 1/R2 + 1/R456789 = 1/1200 Ω + 1/400 Ω = (1 + 3)/1200 Ω = 4/1200 Ω, so R2456789 = 300 Ω.
- Add R1 and R3 in series with R2456789: R_total = R1 + R2456789 + R3 = 1000 Ω + 300 Ω + 1200 Ω = 2500 Ω.
- Use Ohm’s Law to find total current: I_total = V_T / R_total = 50 V / 2500 Ω = 0.02 A or 20 mA.
Parent Tip: Review the logic above to help your child master the concept of parallel circuit problems worksheet.
