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WorksheetsModule K Magnets
Total questions: 20
Worksheet time: 31mins
Jesse tests three magnets by observing how many paper clips he can attach to the north pole in a single chain. He finds that Magnet A holds six paper clips, Magnet B holds five paper clips, and Magnet C holds two paper clips. He warms Magnets A and C in the oven for a few minutes and repeats his procedure. This time, Magnet A holds only four paper clips, Magnet B still holds five paper clips, and Magnet C cannot hold any paper clips. Which statement explains Jesse’s observations?
Warming a magnet unaligned some of the magnetic domains.
The forces produced by a magnet naturally become weaker over time.
Warming a magnet causes the distance of its magnetic force to decrease.
The poles of the magnet become reversed when warmed and cause it to repel the paper clips.
The picture shows two magnets interacting with uncharged iron filings.
What relationship is shown in the picture?
Electric force between like ends is attractive.
Magnetic force between like ends is attractive.
Electric force between opposite ends is attractive.
Magnetic force between opposite ends is attractive.
Kim has a loop of wire and a magnet. Which of these will create the largest electric current in the loop?
Wrap the wire tightly around the magnet.
Place the magnet in the center of the wire.
Move the magnet quickly through the loop.
Spin the loop of wire slowly above the magnet.
The diagram shows a balloon that was rubbed with a piece of cloth.
Which statement describes the charges shown?
Negative charges from the cloth were transferred to the balloon.
Balloons always have more negative charges than positive charges.
Negative charges appeared when the cloth was rubbed on the balloon.
Some of the positive charges on the balloon disappeared when it was rubbed by the cloth.
Rohit is using a compass to investigate magnetic forces. Which of these will cause the compass to change direction?
plastic paper clips
a wooden doorknob
the wire he is using to charge a cell phone
the wire going from the wall to an unlit lamp
Sachdev finds two metal bars and decides that since they are stuck together, at least one of metal bars must be a magnet. Sachdev pulls the bars apart and uses a marker to label each end of the bars. She lays bar CD on the table and then ties a string around bar AB and hangs end A above end D, as shown in the diagram.
Sachdev finds that the end marked A tips downward until it is touching the end marked D. Which test allows Sachdev to draw a conclusion about the magnetic properties of each metal bar?
She hangs A directly above C and sees that the two ends attract. She concludes that both bar AB and bar CD always produce magnetic fields.
She hangs B directly above C and sees that the two ends attract. She concludes that both bar AB and bar CD always produce magnetic fields.
She hangs B directly above C and sees that the two ends attract. She concludes that bar CD always produces a magnetic field, but bar AB only temporarily produces a magnetic field.
She hangs A above the center of bar CD and finds that A is only weakly attracted to CD. She concludes that bar CD always produces a magnetic field, but bar AB only temporarily produces a magnetic field.
A bar magnet is placed flat on a table. A smaller bar magnet is held vertically just above the first one, with the south pole close to the first magnet and the north pole farther away. The diagram shows the larger bar magnet.
Which options has the locations circled where the smaller magnet would encounter the strongest magnetic forces.
Several pairs of charged objects are held at different distances, and the force between each pair is measured. Each object has the same amount of charge, q, but it can be positive or negative.
Number the descriptions from 1 to 4 with 1 as the smallest force and 4 as the largest force.
_____+q and +q at a distance of 2.0 cm
_____+q and +q at a distance of 4.0 cm
_____+q and -q at a distance of 1.0 cm
_____+q and -q at a distance of 3.0 cm
2,4,3,1
1,2,3,4
4,2,1,3,
2,4,1,3
Two magnets are shown in the diagram. Magnet A is glued to the table, and Magnet B is free to move.
Which sentence form the paragraph below explains Magnet B's motion?
There is a magnetic field around Magnet A, and a magnetic field around Magnet B. These magnetic fields extend in all directions around the magnets but cancel each other out. The magnetic field around Magnet A exerts a force on Magnet B, so Magnet B moves downward and to the right.
There is a magnetic field around Magnet A, and a magnetic field around Magnet B.
These magnetic fields extend in all directions around the magnets but cancel each other out.
The magnetic field around Magnet A exerts a force on Magnet B, so Magnet B moves downward and to the right.
None of these
The diagram shows a device called a capacitor. In a capacitor, metal plates are separated by an insulating material that keeps charges from transferring between the plates. By running current through the wires, the two parallel metal plates within the capacitor become oppositely charged. Note that only the top metal plate is shown in the diagram.
Which of these would increase the strength of the electric force between the plates?
Reverse the wires to switch the charges of the plate.
Increase the thickness of the insulating material.
Increase the thickness of the plastic coating.
Decrease the current in the wires
None of these. The options listed would either decrease strength ot the would be no change in strength.
Diagram 1 shows ferromagnetic material in close range with a nonmagnetic material. Diagram 2 shows ferromagnetic material in close range with a magnetic material. Diagram 3 shows a magnet that has been cut in half to show how the two halves interact. Arrangements of magnetic domains are in the boxes.
Write the letters of the magnetic domain arrangements in the empty boxes for diagrams 1, 2, and 3.Some letters may be used more than once or not at all.
Which option correctly matches the magnetic domain with the correct diagram.
Gundeep tapes a bar magnet to the wall. He tapes a second bar magnet to a small aluminum lab car and moves the car into place near the wall as shown in the diagram. When he releases the car, it begins to move slowly away from the wall. He would like to run his experiment again to test other situations.
Which of the following would cause the car to move slowly toward the wall?
He positions the car close to the wall.
He replaces the bar magnet on the wall with a stronger magnet in the same direction
He positions the car closer to the wall and reverses the orientation of the magnet on the car.
He positions the car farther from the wall and reverses the orientation of the magnet on the wall.
Which of the images show positively charged objects?
Karin has a tray with sand and iron shavings mixed together. She wants to use the iron shavings to study magnetic fields. She decides to design a device that will separate the iron shavings from the sand and later release them into a separate container.
Karin looked around her home and found these items:
box batteries insulated wire
cup iron bolts refrigerator magnets
glue paper clips
tape wire cutters
Select all that would be a criterion that can be satisfied by an electromagnet or a permanent magnet?
attracts iron but not sand
can scoop up the iron and sand mixture
can release the iron shavings after they are collected
can be constructed from or found among the items in Karin's home
Mia finds that when she places a needle near a magnet, the needle rotates to point toward the south pole of the magnet. Mia claims this provides evidence that there is a magnetic field that affects both objects.
Explain why the needle rotated when Mia placed it near the magnet.
Explain why the motion of the needle does or does not provide evidence to support Mia’s claim.
There was a magnetic force from the magnet on the needle. This magnetic force pulled on the end of the needle, making it rotate toward the magnet.
The needle can move only if there's a force, but the magnet and needle were not in contact. Therefore, there must be a magnetic field between the magnet and needle to provide the magnetic force.
The magnetic force does not act on the needle. It is the spin of the Earth that causes it to move
If there were no force it would still move.
The model shows two planets that will attract a spacecraft from a distance.
Explain what the arrows around the planets represent.
Using the model, describe how Planet A and Planet B differ.
Describe how the path of a spacecraft flying by each of the two planets would be affected.
The arrows in the model represent the gravitational fields of the planets.
Planet A has more arrows around it, which shows that the gravitational field of Planet A is stronger than the gravitational field of Planet B.
The gravitational field of planet A is stronger than the gravitational field of Planet B, so Planet A would exert a stronger gravitational force on the spacecraft than Planet B would. When a spacecraft is flying by, the gravitational force will cause its path to curve toward the planet. The amount that it curves will be greater for Planet A than for Planet B because the gravitational force is stronger.
The arrows means that there is less gravity. If if the is less gravity then spaceships would not be able to land. The spaceship would just travel past the planet.
This incomplete model shows three electrically charged objects that are interacting with each other.
Explain what the arrows around the objects represent.
Use the model to determine the charges of objects A and B.
Describe how the model would change if the charge of object A is doubled.
The arrows in the model represent the electric fields of the charged objects. Electric fields are areas around objects where electric forces can act.
Like charges repel, so object A must also have a positive charge. Because the arrows connect objects A and B, the objects are attracting. Since object A is positive, and opposites attract, object B must be negative.
If the charge of object A is doubled, then it has a stronger electric field, so there should be twice as many lines to represent the increased strength of the electric field around it.
Object B, must have a positive charge because A is also positive and like charges attract.
Based on her experiments, what hypothesis is Leisha testing?
An electromagnet exerts stronger forces on iron than on other metals.
An electromagnet produces stronger magnetic forces closer to the magnet.
An electromagnet produces both repulsive and attractive magnetic forces.
An electromagnet’s south pole produces stronger magnetic forces than its north pole.
Leisha brings an electromagnet toward a piece of iron and observes that the piece of iron starts to move when the electromagnet is 6 cm away. She plans to add another 25 coils of wire to the electromagnet. Which statement explains what will happen when she brings her modified electromagnet near the piece of iron?
The strength of the magnetic force will change, so the iron will start to move when the electromagnet is less than 6 cm away.
The strength of the magnetic force will change, so the iron will start to move when the electromagnet is more than 6 cm away.
The strength of the magnetic force will change, but the iron will still start to move when the electromagnet is exactly 6 cm away.
The strength of the magnetic force will not change, so the iron will still start to move when the electromagnet is exactly 6 cm away.
Leisha thought of three ways she could change her experimental procedure:
1. Observe the direction the bar magnet moves when she brings it near the end of the nail.
2. Observe how many paper clips she can attach to the end of the nail.
3. Connect each wire to the opposite end of the battery as before.
She wants to know how changing the direction of electric current in an electromagnet affects the magnetic force.
Identify which of these modifications Leisha should use in her new experiment.
Explain how each modification you selected will help her meet the goals of her investigation.
Leisha should use 1,2,and 3.
Connecting the wires to different ends of the battery will reverse the current. She can use the paperclips to see if the strength of the magnetic force changed after she changed the direction of the current because if the magnet is stronger, it will hold more paperclips. She can use the bar magnet to test the direction of the magnetic field because the electromagnet will repel the like pole or attract the opposite pole.
She could use a compass to direct the magnetic field in the direction she needs it to go. Because the needle is magnetic she can move the field toward or away from the paperclips.
An iron nail could be used to see how strong the paper clips are.
