Respuesta :
.
A positive charge, Q, is located in a magnetic field, B, which is directed toward the right, as shown in the figure
above. If Q travels toward the top of the page, the direction of the magnetic force on Q is
a. toward the right. c. away from you, into the page.
b. toward you, out of the page. d. There is no magnetic force.
12. Which conversion process is the basic function of the electric motor?
a. mechanical energy to electrical energy
b. electrical energy to mechanical energy
c. low voltage to high voltage, or vice versa
d. alternating current to direct current
13. There are four coils of wire being used as electromagnets. They all have the same size and are made up of the same
material but have a different number of loops. Which coil will produce the weakest magnetic field when the same
amount of current passes through all of the coils?
a. a coil having 10 loops c. a coil having 30 loops
b. a coil having 25 loops d. a coil having 45 loops
14. A/An _____ is a long coil of wire with many loops used to create a large magnetic field.
a. solenoid c. electric motor
b. electromagnet d. armature
15. A/An _____ is described as the area around a magnet where other magnets would be accelerated.
a. magnetic field c. domain
b. magnetic flux d. solenoid
16. Which factor will not affect the strength of a solenoid?
a. number of wraps c. radius of the wraps
b. strength of current d. core type
17. What are the units of electromotive force?
a. newtons c. volts
b. newtons per coulomb d. volts per ampere
18. The number of turns on the primary coil of a step-down transformer _____ the number of turns on the secondary
coil.
a. equals c. is less than
b. is greater than d. is unrelated to
19. A generator is used to light a bulb. Energy for lighting the bulb actually comes from
a. a plug where the generator is connected to the wall.
b. a mechanical input to the generator.
c. the magnet in the generator.
d. the coil of wire.
e. none of the above
20. The principal advantage of AC power over DC power is that
a. AC voltage oscillates, whereas DC voltage does not.
b. lower voltages are used.
c. AC circuits multiply power more easily.
d. AC voltage can be transformed more easily.
e. AC circuits are safer.