1. Chapter 17
Introduction to Electricity
Preview
CRCT Preparation

2. Chapter 17
CRCT Preparation
1. The diagram shows four light bulbs wired in a circuit. What would happen if bulb 3 burned out?
A Bulb 1 and bulb 2 would go out but bulb 4 will remain lit.
B Bulb 2 and bulb 4 would go out but bulb 1 will remain lit.
C All of the other bulbs would go out.
D All of the other bulbs would remain lit.

3. Chapter 17
CRCT Preparation
1. The diagram shows four light bulbs wired in a circuit. What would happen if bulb 3 burned out?
A Bulb 1 and bulb 2 would go out but bulb 4 will remain lit.
B Bulb 2 and bulb 4 would go out but bulb 1 will remain lit.
C All of the other bulbs would go out.
D All of the other bulbs would remain lit.

4. Chapter 17
CRCT Preparation
2. Tara rubs a balloon on her hair and charges both the balloon and her hair. What will happen if Tara holds the balloon close to her hair?
A Her hair will be repelled by the balloon because her hair and the balloon have the same charge.
B Her hair will be attracted to the balloon because her hair and the balloon have the same charge.
C Her hair will be repelled by the balloon because her hair and the balloon are oppositely charged.
D Her hair will be attracted to the balloon because her hair and the balloon are oppositely charged.

5. Chapter 17
CRCT Preparation
2. Tara rubs a balloon on her hair and charges both the balloon and her hair. What will happen if Tara holds the balloon close to her hair?
A Her hair will be repelled by the balloon because her hair and the balloon have the same charge.
B Her hair will be attracted to the balloon because her hair and the balloon have the same charge.
C Her hair will be repelled by the balloon because her hair and the balloon are oppositely charged.
D Her hair will be attracted to the balloon because her hair and the balloon are oppositely charged.

6. Chapter 17 3. How does the electric force act within an atom?
CRCT Preparation
3. How does the electric force act within an atom?
A The electric force causes the repulsion of the negatively-charged electrons from the positively-charged nucleus.
B The electric force causes the attraction of negatively-charged electrons to the positively charged nucleus.
C The electric force holds neutrons and protons together in the nucleus.
D The electric force causes the attraction of negatively-charged electrons to each other.

7. Chapter 17 3. How does the electric force act within an atom?
A The electric force causes the repulsion of the negatively-charged electrons from the positively-charged nucleus.
B The electric force causes the attraction of negatively-charged electrons to the positively charged nucleus.
C The electric force holds neutrons and protons together in the nucleus.
D The electric force causes the attraction of negatively-charged electrons to each other.

8. Chapter 17
CRCT Preparation
4. When Andre plugs his stereo into the same outlet as the television and lamp, all three won’t work. What is the most likely hypothesis for what happened?
A The circuit was overloaded, and the circuit breaker opened.
B The circuit was complete, and the circuit breaker closed.
C Only the stereo operates on alternating current.
D The stereo’s electrical cord was faulty.

9. Chapter 17
CRCT Preparation
4. When Andre plugs his stereo into the same outlet as the television and lamp, all three won’t work. What is the most likely hypothesis for what happened?
A The circuit was overloaded, and the circuit breaker opened.
B The circuit was complete, and the circuit breaker closed.
C Only the stereo operates on alternating current.
D The stereo’s electrical cord was faulty.

10. Chapter 17
CRCT Preparation
5. Which of the following electrical devices could be used to monitor the temperature of an engine?
A a thermocouple
B a photocell
C a dry cell
D a battery

11. Chapter 17
CRCT Preparation
5. Which of the following electrical devices could be used to monitor the temperature of an engine?
A a thermocouple
B a photocell
C a dry cell
D a battery

12. Chapter 17
CRCT Preparation
6. A scientist measured the distance between two positively-charged objects and determined the electric force between them. Based on the data in the table, which of the following statements is true?
A As the distance between the objects increases, the size of the electric force decreases.
B As the distance between the objects increases, the objects become more positively charged.
C The size of the electric force is constant.
D As the size of the objects increases, the size of the electric force between them decreases.

13. Chapter 17
CRCT Preparation
6. A scientist measured the distance between two positively-charged objects and determined the electric force between them. Based on the data in the table, which of the following statements is true?
A As the distance between the objects increases, the size of the electric force decreases.
B As the distance between the objects increases, the objects become more positively charged.
C The size of the electric force is constant.
D As the size of the objects increases, the size of the electric force between them decreases.

14. Chapter 17
CRCT Preparation
7. Suki can have all five appliances in her kitchen on at the same time, or she can have each appliance on one at a time. How are the appliances in Suki’s kitchen wired?
A in a single loop
B in a direct current circuit
C in a parallel circuit
D in a series circuit

15. Chapter 17
CRCT Preparation
7. Suki can have all five appliances in her kitchen on at the same time, or she can have each appliance on one at a time. How are the appliances in Suki’s kitchen wired?
A in a single loop
B in a direct current circuit
C in a parallel circuit
D in a series circuit

16. Chapter 17
CRCT Preparation
8. How should Pedro wire four bulbs in a circuit so that all the bulbs shine as brightly as possible?
A He should wire all four bulbs in a series circuit.
B He should wire two bulbs in a parallel circuit and the other two bulbs in a series circuit.
C He should wire three bulbs in a series circuit and the other bulb in a parallel circuit.
D He should wire all four bulbs in a parallel circuit.

17. Chapter 17
CRCT Preparation
8. How should Pedro wire four bulbs in a circuit so that all the bulbs shine as brightly as possible?
A He should wire all four bulbs in a series circuit.
B He should wire two bulbs in a parallel circuit and the other two bulbs in a series circuit.
C He should wire three bulbs in a series circuit and the other bulb in a parallel circuit.
D He should wire all four bulbs in a parallel circuit.

18. Chapter 17
CRCT Preparation
9. Which of the following copper wires will have the least amount of resistance?
A a short, thin wire
B a short, thick wire
C a long, thin wire
D a long, thick wire

19. Chapter 17
CRCT Preparation
9. Which of the following copper wires will have the least amount of resistance?
A a short, thin wire
B a short, thick wire
C a long, thin wire
D a long, thick wire

20. Chapter 17
CRCT Preparation
10. Two kinds of electric current exist: direct current and alternating current. Explain the difference between these two kinds of current and give an example of where you might find each kind of current.

21. Chapter 17
CRCT Preparation
10. Answer –
In direct current, the charges always flow in the same direction. In alternating current, the charges continually shift from flowing in one direction to flowing in the reverse direction. Students should give at least one example of direct current being used. Any battery-operated device, such as a flashlight or an MP3 player, is an acceptable example. Students should give at least one example of alternating current being used. Any electrical device that is plugged into an outlet, such as a lamp or a fan, is an acceptable example.

22. Chapter 17
CRCT Preparation
11. On a rainy day, David wears rubber boots to school. The floors in his math classroom are covered with carpet. After David walks across the room to the pencil sharpener, he gets a shock when he touches the sharpener. Explain why David got a shock.

23. Chapter 17
CRCT Preparation
11. Answer –
When David walked across the room, his rubber boots rubbed the carpet and electrons from the carpet were transferred to David. Negative charges built up in David as static electricity. The static electricity discharged rapidly when David touched the sharpener. The discharge gave David a shock.