Basic Circuit Analysis
Combination Series-Parallel Circuits

Section 3-3 Voltage in Combination Circuits

Procedure

 Given the value of VT and the three resistors, determine: RT, IT IR1,VR1 VR2,VR3 IR2, IR3

1. Find the total resistance

RT = R1 + (R2 || R3)

2. Determine the total current Ohm's Law

 IT = VT RT

3. Find the current through R1 (same as IT)

IR1 = IT

4. Determine the voltage across R1Ohm's Law

VR1 = IR1R1

5. Determine the voltage across R2 Kirchhoff's Voltage Law

VR2 = VT VR1

6. Find the voltage across R3 -- Property of parallel resistors

VR3 = VR2

7. Determine the current through R2 Ohm's Law

 IR2 = VR2 R2

8. Determine the current through R3 Kirchhoff's Current Law

IR3 = IR1IR2

Procedure

 Given the value of VT and the four resistors, determine: RT, IT IR1,VR1 IR2,VR2 IR3, VR3 IR4, VR4

1. Calculate the total Resistance

RT = R1 || R2 + R3 || R4

2. Determine the total current Ohm's Law

 IT = VT RT

3. Determine the voltage across R1 Ohm's Law

VR1 = IT(R1 || R2)

4. VR2 = VR1 -- Property of parallel resistors

5. Determine the current for R1

 IR1 = VR1 R1

6. Determine the current for R2 Kirchhoff's Current Law

IR2 = IT - IR1

7. Determine the voltage across R3 Kirchhoff's Voltage Law

VR3 = VT -VR1

8. Determine the voltage acrossR4  Property of parallel resistors

VR4 = VR3

9. Calculate the current for R3 -- Ohm's Law

 IR3 = VR3 R3

10. Determine the current for R4 Kirchhoff's Current Law

IR4 = IT - IR3

Procedure

 Given the value of VT and the three resistors, determine: RT, IT IR1,VR1 IR2,VR2 IR3, VR3

Procedure

 Given the value of VT and the four resistors, determine: RT, IT IR1,VR1 IR2,VR2 IR3, VR3 IR4, VR4

Procedure

 Given the value of VT and the four resistors, determine: RT, IT IR1,VR1 IR2,VR2 IR3, VR3 IR4, VR4