Download Series Circuits

Name
Date
Electric Circuits
Series Circuits
Instructions: Do every problem using LEPA on a separate sheet of paper.
1. A 5-ohm resistor, a 13-ohm resistor and a 22-ohm resistor are connected in series.
a. What is the equivalent resistance? 40 Ω
b. What is the current when the resistors are connected to a 20-volt battery? 0.5 A
c. What is the potential difference across each resistor? 2.5 V, 6.5 V, 11 V
2. A 15-ohm resistor and a 25-ohm resistor are connected in series to a voltage source.
a. When the current through the 15-ohm resistor is 2 amperes, what is the current
through the 25-ohm resistor?
b. What is the equivalent resistance of the circuit? 40 Ω
c. What is the potential difference across the 15-ohm resistor? 30 V
d. What is the potential difference across the 25-ohm resistor? 50 V
3. A 3-ohm resistor and a 6-ohm resistor are connected in series to a 9-volt battery. What is
the current through the 6-ohm resistor? 1 A
4. What is the equivalent resistance of a series circuit that has 3 resistors that each have a
resistance of R?
5. If you add another resistor to a series circuit, what happens to the resistance of the
circuit? If it is connected to a source of constant voltage, what happens to the current?
6. There are three light bulbs connected in series. If one of the three burns out, what
happens to the other two?
7. A 5-volt battery is connected to a 4-ohm resistor and a 6-ohm resistor.
a. What is the power of the 4-ohm resistor? 1 W
b. What is the power of the 6-ohm resistor? 1.5 W
c. What is the total power of the circuit? 2.5 W
8. Can a series circuit be connected with a switch to shut off only one of three lights?
9. Draw the following circuit diagram of a series circuit and find the potential difference,
current, resistance and power for each resistor and the whole circuit:
 A battery of unknown potential difference
 Three resistors
o An unknown resistor
o A 20 Ω resistor
o A 40 Ω resistor
 Two voltmeters
o One measuring the unknown resistor as 5 V
o One measuring the 20 Ω resistor as 10 V
 One ammeter measuring the current from the battery