Tutorial Chapter 4 (Series and Parallel)
A. Series Circuit
1. Determine RT for each circuit in figure 1.
Ans: a) 7.9kΩ b) 33Ω c)13.24MΩ
2. The total resistance in figure 2 is 20kΩ. What the value of R5?
ans: 8.2kΩ
3. The current from the source in figure 3 is 5mA. How much current does each milliammeter in
the circuit indicated?
ans: 5mA
4. Determine voltage across each resistor in figure 4.
Ans: a) 625µA b)4.26µA
5. Three 470 Ω resistor are in series with a 48V source.
a) How much current in there? Ans: 34.0mA
b) What is the voltage across each resistor? Ans: 16V
c) What is the minimum power rating of the resistor? Ans: 0.543W
6. Five resistors are in series with 20V source. The voltage drop across four of the resistors are
1.5V, 5.5V, 3V and 6V. How much voltage across the fifth resistor? Ans:4v
7. Find the voltage between A and B in each voltage divider of figure 5. Ans: a)3.84v b) 6.77v
8. Determine minimum and maximum output voltage from the voltage divider in figure 8b.
Ans: Vmin =3.8v Vmax =9.38v
9. In figure 9, determine:
a) Voltage across R2 ans: 3.62v
b) Voltage at each point with respect to ground. Ans: VA=11.4v, VB=7.76v, VC=7.11v,
VD=647mV
c) What is VAC? Ans: 4.27v
d) What is VCA? Ans: -4.27v
B. Parallel Circuit
1. Calculate RT for each circuit in figure 8
Ans: a) 1.5kΩ , b) 18.2kΩ, c) 892Ω
2. Determine voltage across and current through each parallel resistor if the total voltage is 12V
and the total resistance is 600 Ω. There are four resistors, all equal value.
Ans: v=12v, I=5mA
3. What is the total current, IT in each circuit of figure 9.
Ans: a) IT= 909µA b)IT= 76mA
4. What is the current in each resistor for the circuits shown in figure 10
Ans: a)I1=179µA, I2=455µA b) I1=444µA, I2=80µA
5. Using the current divider formula, determine the current in each branch of the circuit of figure
5.
Ans: a) I1=6.88uA, I2=3.13uA b) I1=5.16mA, I2=2.35mA, I3=1.56mA, I4=921uA
6. Determine total power in each circuit of figure 5.
Ans: a) 68.8uW, b)51.6mW
7. Determine the unknown resistances in figure 7.
Hint: Find V=> I1:1.5mA – 1.2mA= 0.3mA
Ans: Vs= 0.3V , R2=750Ω , R4=423Ω