Electricity and Magnetism Review
True/False -
Indicate whether the sentence or statement is true or false.
1.When you bring the south ends of two magnets close together, they repel each other.
2.The strength of an electromagnet can be increased by reducing the number of turns on the wire coil.
3.An electric motor is used to change mechanical energy into electrical energy.
4.Moving a wire through a magnetic field creates an electrical current in the wire.
5.Current that does NOT reverse direction is called ____.
6.The location of the strongest magnetic forces is the ____.
7.The function of an electric motor is to change ______energy to ______energy.
8.The function of a generator is to change ______energy to ______energy.
9.The current that flows in an electric circuit carries ______energy.
10.Electromagnetic induction is the process of producing an electric current by moving a loop of wire ____.
11.Draw a picture of how the domains in a magnet are arranged.
12.Resistance is measured in a unit called the ____.
13.The statement that current is equal to the voltage difference divided by the resistance is known as____.
14.A path that allows only one route for an electric current is called a ____.
15.Electric charge that has accumulated on an object is referred to as ____.
16.A circuit that has two or more branches for electrons to follow is a(n) ____.
17.The rate at which an electrical device converts energy from one form to another is called ____.
18.A material through which electrons do NOT easily flow is a(n) ____.
19.What do we call a device designed to open an overloaded circuit and prevent overheating?
20.Explain how an electromagnet works.
21.What is the primary purpose of a generator in terms of energy?
22.Explain how a generator works.
23.Why are electromagnets temporary magnets?
24.Is it possible to break a magnet into two pieces so one of the pieces has just one pole? Explain.
25.Name two ways of increasing the magnetic field of an electromagnet.
26.Describe how you could quickly determine whether a string of lights is wired in series or in parallel.
27.Why does a spark jump from your hand to the doorknob as you reach for the door after walking across a carpeted floor?
28.What is static electricity?
29.Why does current generally involve the flow of electrons, but not protons?
Problem
30.An air conditioner uses 1,800 W of power when plugged into a wall socket that operates at a voltage of 210 V. What is the current flowing through the air conditioner?
31.A television that requires an average of 0.40 A of current is operated on a 120-V service for 5.0 hours. How much energy is used?
Figure 7-1
32.In Figure 7-1, circuit ______is wired in series.
33.In Figure 7-1, circuit ______is wired in parallel.
34.In Figure 7-1, circuit ______represents the way that homes are usually wire