AnswersELPGEQ2 MJ Science 3 - 2002100 HCPS v24Magnets and Magnetism

Magnets and Magnetism — Unit test Answers

15 verified answers
1
Free Preview

Measurements of two electric currents are shown in the chart.

Question illustration
A
Current X has a greater potential difference, and the charges flow at a slower rate.
B
Current Y has a greater potential difference, and the charges flow at a slower rate.
C
Current X has a greater potential difference, and the charges flow at a faster rate.
D
Current Y has a greater potential difference, and the charges flow at a faster rate.
2
Free Preview

Which unit is used to measure resistance?

A
volts
B
charges
C
amperes
D
ohms
3

Parker wound a wire around a large iron nail. He then created an electromagnet by connecting the ends of the wire to different batteries. The table shows the current he measured for each electromagnet.

Question illustration
A
Electromagnet W is the strongest.
B
Electromagnet X is weaker than electromagnet Z.
C
Electromagnet Y is the strongest.
D
Electromagnet Y is weaker than electromagnet X.
4

Two bar magnets are held close together. When they are released, they move toward one another. Which best describes the original placement of the magnets?

A
The magnets are placed end to end with the north pole of each pointing toward the other.
B
The magnets are placed end to end with the south pole of each pointing toward the other.
C
The magnets are placed side by side with the like poles of each magnet near the other.
D
The magnets are placed side by side with the opposite poles of each magnet near the other.
5

Which best contrasts an electric generator and an electric motor?

A
In a generator, slip rings function as a solenoid, and in a motor, an armature functions as a solenoid.
B
In a motor, slip rings function as a solenoid, and in a generator, an armature functions as a solenoid.
C
A generator converts electrical energy to kinetic energy, and a motor converts kinetic energy to electrical energy.
D
A generator converts kinetic energy to electrical energy, and a motor converts electrical energy to kinetic energy.
6

Based on illustrations of magnetic field lines, where could an object be placed so it would not experience a magnetic force?

A
halfway between the like poles of two magnets, because the field lines bend away and do not enter this area
B
halfway between the opposite poles of two magnets, because the field lines are the closest together
C
above the middle of a bar magnet, because the magnetic field lines are only found around the sides of the magnet
D
above a pole of a bar magnet, because the magnetic field lines either go in or go out at the end
7

Liang is working with an electrical circuit. She replaces a straight electrical wire with a coiled wire.

A
increase the strength of the magnetic field when current flows through the circuit
B
decrease the strength of the magnetic field when current flows through the circuit
C
increase the current that flows through the wire when the circuit is active
D
decrease the current that flows through the wire when the circuit is active
8

What does voltage describe?

A
how fast current can flow
B
how much current can flow
C
how much a material resists electrical flow
D
how fast a material conducts electrical flow
9

Dr. Eriksson is working on a material called selenium. She is adding a certain number and type of atoms to the selenium, which will control its conductivity.

A
semiconductor
B
conductor
C
superconductor
D
insulator
10

Horatio drew a diagram to illustrate how magnetism is produced by electric currents.

Question illustration
A
Magnetism is not produced by electric currents unless the wire is coiled.
B
The magnetic field does not continually spread outward from the wire.
C
The magnetic field is produced inside the wire, not outside of it.
D
Magnetism is only produced when a metal bar is placed near the wire.
11

Badri makes the table below to review the factors that affect the electric force between objects.

Question illustration
A
changing “Direct” to “Indirect”
B
changing “Indirect” to “Direct”
C
changing “Distance” to “Amount of electric charge”
D
changing “Mass” to “Amount of electric charge”
12

How are the electric field lines around a positive charge affected when a second positive charge is near it?

A
The field lines combine with the lines around the second positive charge.
B
The field lines overlap with the lines from the second positive charge.
C
The field lines bend toward the second positive charge.
D
The field lines bend away from the second positive charge.
13

Look at the circuit diagram.

Question illustration
A
one
B
two
C
three
D
four
14

Which current is produced in homes?

A
magnetic
B
voltage
C
alternating
D
direct
15

A positively charged object is placed to the left of a negatively charged object. Which best describes how the positively charged object will move?

A
to the left, in the direction of the electric field lines
B
to the right, in the direction of the electric field lines
C
up in the direction that the field lines bend away
D
down in the direction that the field lines bend away

Did you find these answers helpful?

More from this Course

Quiz
15 verified answers

Unit Test

Quiz
12 verified answers

Test

Quiz
10 verified answers

Magnets and Magnetism