1. Which of the following statements describes the interaction between magnetic poles?
(1 point)
Like poles attract each other.
Like poles repel each other, and opposite poles attract each other.
Opposite poles repel each other.
Like poles attract each other, and opposite poles repel each other.
2. Which of the following statements is true about Earth’s magnetic poles?
(1 point)
They are located at Earth’s geographic poles.
They are the areas where Earth’s magnetic field is weakest.
They are the areas where Earth’s magnetic field is strongest.
Earth has four magnetic poles.
3. Which of the following statements is true about ferromagnetic materials?
(1 point)
All ferromagnetic materials are permanent magnets.
Ferromagnetic materials that are permanent magnets have domains that are randomly oriented.
Ferromagnetic materials that are permanent magnets have domains that remain aligned for long periods of time.
Ferromagnetic materials do not have domains and cannot be magnetized.
4. If the current in a wire is directed upward, what is the direction of the magnetic field produced by the current?
(1 point)
counterclockwise in the horizontal plane
clockwise in the horizontal plane
in the same direction as the current
in the opposite direction to the current
5. Which of the following statements is true about a current-carrying wire in a magnetic field?
(1 point)
Reversing the current direction will cause the force deflecting the wire to be parallel to the magnetic field.
Reversing the current direction will cause the force deflecting the wire to be perpendicular to the magnetic field but in the opposite direction.
Reversing the current direction will cause the force deflecting the wire to be parallel to the velocity of the charge.
Reversing the current direction will not affect the force deflecting the wire.
6. How can the voltage in a coil of wire be increased in the process of electromagnetic induction?
(1 point)
Move the magnet inside the coil of wire more slowly.
Hold the magnet stationary.
Move the coil of wire slowly, and keep the magnet stationary.
Move the magnet inside the coil of wire more rapidly.
7. A DC generator is similar to an AC generator except that in
(1 point)
DC generators, slip rings produce direct current.
DC generators, commutators produce direct current.
AC generators, commutators produce alternating current.
AC generators, no commutators or slip rings are used.
8. A transformer has a primary coil with 500 turns and a secondary coil with 250 turns. If the output voltage is 240 volts, what is the input voltage?
(1 point)
96 volts
120 volts
480 volts
500 volts
9. How are fossil fuels used to generate electrical energy?
(1 point)
Heat from burning fuel spins magnets inside an electric motor.
Heat from burning fuel creates steam that spins a turbine.
Heat from burning fuel causes an electric motor to produce a current.
Heat from burning fuel creates steam that turns a transformer.
Completion
Complete each sentence or statement.
10. In a solenoid, there will be no magnetic field if there is no ____________________ in the wires of the coil.
(1 point)
11. The statement that a voltage can be induced in a conductor by a changing magnetic field is known as ____________________ law.
(1 point)
12. Large power plants in the United States currently use _________________________ generators.
(1 point)
Short Answer
13. Explain why Earth’s magnetic North Pole would be a south pole of a bar magnet.
(3 points)
14. How does the charge of a particle affect the direction in which the particle is deflected in a magnetic field?
(3 points)
15. What is a generator and how does it work?
(3 points)
16. List five energy sources that are used in the United States to produce electrical energy.
(3 points)
Essay
17. Explain how a step-up transformer is different from a step-down transformer.
(5 points)
