Ch 16 Electricity test reivew
Modified True/False
Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true.
____
1. Different household appliances use electrical energy at different rates. _________________________
____
2. A conductor is a material that doesn't allow electrons to flow through it easily. _________________________
____
3. A lightning bolt occurs when billions of protons are transferred at the same time.
_________________________
____
4. Voltage difference is measured in amperes. _________________________
____
5. The unit used to measure current is the volt. _________________________
____
6. A fuse is a device used to keep electrical circuits from overheating. _________________________
____
7. Ohm's law is the tendency for a material to oppose the flow of electrons. _________________________
____
8. In many circuit diagrams, any electrical device that uses energy is shown with a resistor symbol.
_________________________
____
9. A closed circuit has a break in it. _________________________
____ 10. The ampere is a unit of measurement for voltage. _________________________
____ 11. Electric current flows easily through a conductor. _________________________
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____ 12. If an atom loses electrons, it becomes a
a. negatively charged ion.
b. positively charged ion.
c. neutral atom.
d. neutral ion.
Figure 20-1
____ 13. If the two charges represented in Figure 20-1 were brought near each other, they would
a. attract each other.
c. cause static discharge.
b. repel each other.
d. have no affect on each other.
Completion
Complete each statement.
Select the correct term to complete each sentence. There are extra terms in the list.
resistor
current
positive
voltage
static
decrease
neutral
negative
circuit
circuit breaker
14. Electricity flows through a complete path called a(n) ____________________.
15. An object that has equal amounts of positive and negative charge is considered to be electrically
_____________________.
16. The tiny imbalance of charge that develops on your body as you scuff your feet along a carpet is called
____________________ electricity.
17. Charge is caused to flow by the difference in the____________________ between two points in circuit .
18. Fuses protect a circuit from too much current by creating a break in the circuit but must be replaced. A device
that may be reset while providing the same protection is a(n) _________________________.
19. Like charges ____________________ and opposite charges ____________________.
20. Scientists usually define the direction of current as the direction in which ____________________ charges
would flow.
21. Wood, plastic, and rubber are good electrical ____________________, and copper is a good electrical
____________________.
Short Answer
22. List two materials that are conductors and two materials that are insulators.
23. What happens to the current in a device if the resistance of the device increases and the voltage difference
stays the same?
24. You install two batteries in a flashlight so that their positive ends are connected together. Will the flashlight
work? Why or why not?
25. Explain how a potentiometer is different from a fixed resistor.
Problem
26. Which of the circuits pictured below is an open circuit?
27. What should the voltmeter read (approximately)?
Ch 16 Electricity test reivew
Answer Section
MODIFIED TRUE/FALSE
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
T
F, An insulator
F, electrons
F, volts
F, ampere
T
F, Resistance
T
F, open
F
current
electrical current
11. T
MULTIPLE CHOICE
12. B
13. A
COMPLETION
14.
15.
16.
17.
18.
19.
20.
21.
circuit
neutral
static
voltage
circuit breaker
repel, attract
positive
insulators, conductor
SHORT ANSWER
22. conductors: metals, copper, silver; insulators: plastic, wood, rubber, glass
23. current decreases (Ohm's law)
24. The flashlight will not work because the voltage, or potential difference, across the circuit of the flashlight is
zero.
25. A potentiometer can be adjusted to give a range of resistance; a fixed resistor has a resistance that cannot be
changed.
PROBLEM
26. A
27. voltage of cell #1 + voltage of cell #2 = voltage of meter
1.5 volts + 1.5 volts = 3.0 volts