Module K Magnets

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.

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5

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.

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5

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.

Tags

NGSS.HS-PS2-5

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.

Tags

NGSS.MS-PS2-3

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

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5

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.

Tags

NGSS.MS-PS2-3

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.

• 
• 
• 
• 

Tags

NGSS.MS-PS2-5

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

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5

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

Tags

NGSS.MS-PS2-2

NGSS.MS-PS2-5

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.

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5