Category 1
Which factor can increase the strength of an electromagnet?
A. Fewer coils of wire B. More coils of wire
C. Less current D. Removing the iron core
B. More coils of wire.
Student tests an electric motor using 1 magnet, 2 magnets, and 3 magnets. The motor spins fastest with 3 magnets. What factor is the student investigating?
A. Wire length
B. Battery size
C. Number of magnets
D. Mass of the motor
C. Number of Magnets
Which question would provide the best testable investigation about magnetic force?
A. Are magnets cool?
B. How does the number of magnets affect the speed of an electric motor?
C. Why are magnets interesting?
D. What color magnet is best?
B. How does the number of magnets affect the speed of an electric motor?
Which material is most likely to be attracted to a magnet?
A. Plastic
B. Wood
C. Iron
D. Glass
C. Iron
What do iron filings usually form around a bar magnet?
A. Random circles
B. Patterns showing the magnetic field
C. A solid block
D. Electrical circuits
B. Patterns showing the magnetic field
A student builds two electromagnets. Electromagnet A has 10 coils of wire, and Electromagnet B has 30 coils. Which question would best help determine how the number of coils affects magnetic force?
A. Which wire is longer?
B. Does the electromagnet with more coils pick up more paper clips?
C. Which battery is newer?
D. Which magnet looks better?
B. Does the electromagnet with more coils pick up more paper clips.
1 magnet → 20 rotations/min; 2 magnets → 40 rotations/min; 3 magnets → 60 rotations/min. What pattern does the data show?
A. More magnets decrease speed
B. Speed stays constant
C. Magnets have no effect
D. More magnets increase motor speed
A student uses magnets of different strengths and measures how fast an electric motor spins. What factor is being tested?
A. Magnet strength
B. Wire color
C. Motor weight
D. Room temperature
A. magnet strength
What causes a magnet to attract certain objects?
A. Magnetic force
B. Gravity
C. Friction
D. Sound
A. Magnetic Force
Where is the magnetic force generally strongest on a bar magnet?
A. At the center
B. At every point equally
C. Only on the sides D. At the poles
D. At the poles
An electromagnet with 20 coils picks up 8 paper clips. An electromagnet with 40 coils picks up 16 paper clips. What does the data suggest?
A. More coils decrease magnetic force
B. Coils have no effect
C. More coils increase magnetic force
D. The battery has no effect
C. More coils increase magnetic force
A student wants to determine whether the number of wire coils affects electromagnet strength. Which variable should the student change?
A. Number of wire coils
B. Type of paper clips
C. Room temperature
D. Size of the table
A. Number of wire coils
If you cut a bar magnet in half, what happens?
A. One half becomes north and one half becomes south
B. The magnet completely loses its magnetic force
C. The pieces become electrically charged D. Both pieces can have north and south poles
D. Both pieces can have north and south poles
A strong magnet can attract an object from farther away than a weak magnet. What does this suggest?
A. Stronger magnets have stronger magnetic fields
B. Weak magnets have stronger fields
C. Distance does not matter
D. Gravity causes magnetism
A. Stronger magnets have stronger magnetic fields.
A student gets these results:
What conclusion is best supported?
A. Magnetic force becomes weaker as distance increases
B. Magnetic force becomes stronger as distance increases
C. Distance does not affect magnetic force
D. Magnets only work at 8 cm
A. Magnetic force becomes weaker as distance increases.
Which question could a student ask to investigate the strength of an electric force?
A. What color is the wire?
B. What type of battery looks best?
C. How long is the table?
D. How does increasing the amount of electric charge affect the force?
D. How does increasing the amount of electric charge affect the force?
Why should a student keep the battery the same when testing different numbers of coils on an electromagnet?
A. To make the experiment fair
B. To make the magnet look the same
C. To increase gravity
D. To change the wire color
A. to make the experiment fair
Which investigation would provide the strongest evidence about whether the number of coils affects electromagnet strength?
A. Change coils and battery voltage together
B. Change the type of wire and number of coils
C. Change only the number of coils while keeping other factors constant
D. Test only one electromagnet
C. Change only the number of coils while keeping other factors constant.
Magnet A attracts a paper clip from 8 cm away. Magnet B attracts it from only 3 cm away. Which magnet appears stronger?
A. Magnet A
B. Magnet B
C. They are exactly the same
D. There is not enough information
A. Magnet A
A student claims, "Magnets can only exert a force when they touch an object." Which observation would disprove the claim?
A. A magnet attracts a paper clip before touching it
B. A magnet touches a paper clip
C. A magnet is placed on a table
D. A paper clip touches another paper clip
A. A magnet attracts a paper clip before touching it
Two magnets are placed near each other. What would most likely happen if the strength of one magnet increased?
A. The magnetic force could increase
B. The magnets would stop interacting
C. Gravity would disappear
D. The magnets would become electrically charged
A. The magnetic force could increase.
An electromagnet with 10 coils picks up 5 paper clips. An electromagnet with 20 coils picks up 10 paper clips. What conclusion is best supported by the data?
A. Doubling the coils doubled the number of paper clips picked up
B. Coils have no effect
C. Fewer coils create more force
D. The electromagnet became weaker
A. Doubling the coils doubled the number of paper clips picked up.
An electromagnet with 5 coils picks up 4 paper clips. With 10 coils, it picks up 8 paper clips. If the pattern continues, how many paper clips might it pick up with 15 coils?
12 paper clips
Which statement best explains why magnets can affect objects without touching them?
A. Gravity causes all magnetic interactions
B. Magnets must always touch objects C. Magnetic fields allow magnetic forces to act at a distance D. Magnets only work through direct contact
C. Magnetic fields allow magnetic forces to act at a distance.
A student investigates whether magnet strength affects the distance at which a magnet can attract a paper clip. What is the dependent variable?
A. Magnet strength
B. Type of magnet
C. Distance at which the paper clip is attracted
D. Size of the paper clip
C. Distance at which the paper clip is attracted