Chapters 17 and 18 Practice Packet (not Ohmwork)
Name ________________________
Read Chapters 17 and 18, pages 594 – 600, 608 – 615, 618 – 623, 640 - 656. Answer the following question using your
book and your notes.
Introduction to Electrical Energy and Circuits
1) What is electric potential energy?
2) What is the difference between electrical potential energy and electric potential?
.
3) What is the difference between electric potential and potential difference?
4) What is the unit for potential difference?
5) What is electric current?
6) What is the unit for current?
7) The electric company sells ________________ not ____________________.
8) What is resistance?
9) What does the resistance depend mostly on?
10) What three other factors affect the resistance of a conductor?
11) In an analogy of water flowing through a pipe, what would correspond to the water pressure?
What would correspond to the water flowing through the pipe?
What would correspond to the diameter of the pipe?
12) Each of the wires below is made of copper and they are at the same temperature.
a)
c)
b)
d)
Which wire has the greatest resistance? ____________
Which wire has the least resistance? ___________
13) For a constant resistance how are the potential difference and the current related?
Directly proportional or inversely proportional
14) If the potential difference across a conductor is constant, how is the current related to the resistance?
Directly proportional or inversely proportional
15) Explain why the resistance of a material should increase as the temperature increases.
For the following problems, show your work and the correct units.
16) A 30 ohm toaster is plugged into an outlet in your house which has 120 volts of potential difference. What current
flows?
17) A 3 volt battery causes 0.15 amps of current to flow through a light bulb, what is the resistance of the light bulb?
18) A 100 ohm resistance has 3.5 amps of current flowing through it, what is the voltage?
19) A closed conductive pathway through which current flows is called a ________________.
20) Draw a circuit with a 60 volt potential and a 15 ohm resistor. What is the current flowing through the circuit?
Show your work and the correct units.
21) In order to measure the voltage in a circuit, the voltmeter must be in _____________ with the rest of the circuit.
22) In order to measure the current in a circuit, the voltmeter must be in _____________ with the rest of the circuit.
Series and Parallel Circuits
23) For the circuit diagram below calculate the quantities indicated.
24) For the circuit diagram below calculate the quantities indicated.
25) In a series circuit, the current is the _____________ everywhere.
26) As more resistors are put into a series circuit, the overall current ___________________.
27) As more resistors are put into a parallel circuit, the overall resistance of the circuit ___________________.
28) In a parallel circuit, the volatage drop across one resistor equals the _____________ ______________.
Electric Current
29) What is the difference between direct current and alternating current?
30) Which type of current is supplied to your appliances at your home?
31) For each quantity determine if it is a unit of power or energy.
Watt
Kilowatt
Kilowatt-hour
32) How do you convert watt-hour to kilowatt-hour?
33) If electrical energy is transmitted long distances, the resistance of the wires becomes significant. Why?
34) A 40 watt light bulb is running on 120 volts in your house. What is the current in the light bulb?
35) What is the resistance in the light bulb in the previous question?
36) If you burn a 40 watt light bulb as a night light for 12 hours a day for one week, how many kilowatt hours of
energy were used?
37) If your energy cost is 7.3 cents per kilowatt-hour, how much does it cost to operate the light bulb above?
38) Looking at last month’s electric bill I used 936 kilowatt-hours of energy. How many continuous years can I run a
40 watt light bulb with that many kilowatts of energy? (Remember to change kilowatt-hours to watt hours)