Final - Electromagnetism

Question 1

weakly repelled from both poles, cannot be magnetized

Answer 1

diamagnetic

Question 2

2 diamagnetic examples

Answer 2

water, plastic

Question 3

weakly attracted to both poles; no permanent magnetism

Answer 3

paramagnetic

Question 4

strong attraction; can be permanently magnetized

Answer 4

Ferromagnetic

Question 5

Ferromagnetic example:

Answer 5

Iron

Question 6

What is the smallest unit of magnetism?

Answer 6

There isn’t one

Question 7

How ferromagnetic materials are made into magnets - heat or time in magnetic field can cause permanent magnetism.

Answer 7

induction

Question 8

The force of the magnetic field is ____ proportional to the product of the field strengths

Answer 8

directly

Question 9

The force of the magnetic field is ____ proportional to the square of the distance.

Answer 9

inversely

Question 10

what does a battery do with potential energy?

Answer 10

stores it

Question 11

Explain the right hand rule.

Answer 11

The magnetic field runs perpendicular to the current in a counterclockwise motion - thumb is direction of current, curled fingers are direction of magnetic field.

Question 12

Faraday’s Law:

Strength of the magnetic field – ____ magnetic field = ____ current flow

Answer 12

higher, higher

Question 13

Faraday’s Law:

Velocity of moving magnetic field – ____ velocity = ____ current flow

Answer 13

higher, higher

Question 14

Faraday’s Law:
Magnitude of the induced current depends on the angle of the magnet to the conductor – ____ angle of magnet = ____ current flow

Answer 14

increasing, lower

Question 15

Faraday’s Law:
Magnitude of the induced current depends on the number of turns in the conductor – more turns on conductor = ____ current flow

Answer 15

higher

Question 16

In an electric motor, electricity produces ____ motion.

Answer 16

mechanical

Question 17

In an electric generation, mechanical motion produces ____.

Answer 17

electricity

Question 18

A transformer changes intensity alternating ____ & ____.

Answer 18

voltage, current

Question 19

Transformer law says transformer voltage ratio is ____ related to the turns ratio.

Answer 19

directly

Question 20

𝑁𝑠/𝑁𝑝 = ____.

Answer 20

turns ratio

Question 21

Vs > Vp is a step ____ transformer.

Answer 21

up

Question 22

Vp > Vs is a step ____ transformer.

Answer 22

down

Question 23

Transformer law says transformer current ratio is ____ related to the turns ratio.

Answer 23

inversely

Question 24

A closed-core transformer has a single ____ core and ____ voltage/current.

Answer 24

ferromagnetic, constant

Question 25

An autotransformer has:

1. ____ wire, ____ taps
2. ____ voltage/current
3. small ____

Answer 25

1. single, multiple
2. variable
3. step up/down

Question 26

Shell-type transformer has ___ closed cores and is more ____.

Answer 26

2, efficient