1. Worksheet: Circuits and Ohm’s Law
Chapter 35
Worksheet: Circuits and Ohm’s Law

2. EQUATIONS

3. ELECTRICAL CIRCUIT SYMBOLS

4. 1. Draw a circuit schematic (diagram) to include a
50.0 V battery, an ammeter, and a resistance of
10.0 Ω in series. A + -
50.0 V
10.0 Ω

5. a. What is the reading on the ammeter?+ -
50.0 V
10.0 Ω

6. b. In which direction is the current flowing?
Conventional current (+) A + -
50.0 V
10.0 Ω
Electron flow (-)

7. 2. How much current flows through a radio speaker that has a resistance of 4.0 Ω when 16 V is impressed across the speaker?

8. Draw a circuit diagram of the circuit described in the question above
Draw a circuit diagram of the circuit described in the question above. Include a 6 V battery, an ammeter (labeled with value of current), and a resistance of 3.0 Ω (the speaker). Also label the direction of the conventional (+) current.
2 A
Conventional current A + -
6 V
3.0 Ω

9. 4. The following questions pertain to the circuit diagramed to the right.
a. Lamp A reads a voltage of 12 V. What is the voltage of lamp B?

10. 4. The following questions pertain to the circuit diagramed to the right.
a. Lamp A reads a voltage of 12 V. What is the voltage of lamp B?
Since this is a parallel circuit, the voltage in each branch of the circuit is equal to the voltage source.
Therefore, Voltage is equal to 12 volts in each lamp

11. b. If the ammeters on both branches read the same amount, what does this tell you about the resistance of the two branches?

12. b. If the ammeters on both branches read the same amount, what does this tell you about the resistance of the two branches?
Since this is parallel circuit, the resistance in each branch can be calculated with the following equation:
Since the voltage and current are the same in each branch, the resistance will be the same
Rearrange and get

13. c. If the current flowing in the first branch was 4. 0 A and 6
c. If the current flowing in the first branch was 4.0 A and 6.0 A in the second branch, what would the total current in the circuit be?

14. c. If the current flowing in the first branch was 4. 0 A and 6
c. If the current flowing in the first branch was 4.0 A and 6.0 A in the second branch, what would the total current in the circuit be?
Total current in a parallel circuit can be calculated with the following equation:

15. 5. Draw a series circuit diagram showing a 6
5. Draw a series circuit diagram showing a 6.0 V battery, a resistor, & an ammeter reading of 2.0 A.
2.0 A A
6.0 V

16. a. Label: the size of the resistor, the direction of conventional current, the (+) and (-) terminals of the battery.
2.0 A A
6.0 V

17. a. Label: the size of the resistor, the direction of conventional current, the (+) and (-) terminals of the battery.
2.0 A
Conventional current A + -
6.0 V
3 Ω

18. b. Add a voltmeter to you diagram and indicate the potential difference across the resistor.
Therefore Vs = V1 = 6.0 V

19. 6. Draw a circuit diagram showing a heater with a
resistance of 6 Ω, and a potential difference
source of 24.0 V. A
24.0 V V 6Ω

20. a. Calculate the current through the resistance
24.0 V V 6Ω

21. b. What thermal energy is supplied by the
heater in 10 seconds? (HINT- use the equation
E = I2Rt to determine energy) A
24.0 V V 6Ω

22. 7. Use the circuit diagram to the right to answer the following questions.
a. What is the current flowing through this series circuit if the total resistance is 20 Ω?

23. b. What would the voltage across each of the three bulbs be
b. What would the voltage across each of the three bulbs be? What could you say about the brightness of each of the bulbs?
Therefore each bulb would have 8 volts and the same brightness

24. c. If two of the bulbs had a total resistance of 15 Ω, what would the resistance of the third bulb be?
If the total resistance equals 20 ohms, then the remaining resistor would have a value of 5 ohms
(20 – 15 = 5)

25. First calculate total resistance
d. What would be the current flowing through the circuit be is the voltage source was 6.0 V, and each of the lamps had a resistance of 2 Ω? 2Ω
6.0V 2Ω 2Ω
First calculate total resistance
Then plug into equation for current

26. 8. Draw a circuit diagram showing three 10 Ω resistors connected in parallel and placed across a 60.0 V battery. A
60.0 V
10Ω
10Ω
10Ω

27. a. What is the equivalent resistance of the
parallel circuit? A
60.0 V
10Ω
10Ω
10Ω
Cross multiply and get

28. b. What is the current through the entire circuit?
R= 3.3 Ω (from earlier problem) A
60.0 V
10Ω
10Ω
10Ω

29. c. What is the current through each branch of
the circuit? A
60.0 V
10Ω
10Ω
10Ω
Since the voltage and resistance are the same in each branch they would have the same current

30. 9. Draw a circuit diagram showing the following: a 800
9. Draw a circuit diagram showing the following: a Ω resistor, a 40 Ω resistor, and a 20 Ω resistor connected in parallel and connected across a 24.0 V battery. A
24.0 V
800Ω
40Ω
20Ω

31. a. What is the equivalent resistance of the
parallel circuit? A
24.0 V
800Ω
40Ω
20Ω
Cross multiply and get

32. b. What is the current through the entire circuit?
From above problem A
24.0 V
800Ω
40Ω
20Ω

33. c. What is the current through each branch of
the circuit? A
24.0 V
800Ω
40Ω
20Ω

34. 10. Answer the following questions about the circuit to the right.
a. What do each of the 4 voltmeters read? 6V
In a parallel circuit, the voltage is the same through each branch and divided by the number of resistors in each branch. Therefore:
VA = 6 V
VB = 6 V
VC = 3 V and VD = 3 V (voltage is split between the two resistors in that branch

35. b. If each of the resistors are identical, and the total current flowing through this parallel circuit is A, what is the total resistance of this circuit? 6V