Electric and Magnetic Forces

Describe how the force between two charged objects changes as the objects move closer to each other.

Answer explanation

As two charged objects move closer to each other, the force between the objects increases.

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5

Two negatively charged metal spheres are being moved closer together. Describe the force they exert on each other.

Answer explanation

The repulsive force increases when two negatively charged metal spheres are moved closer together.

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5

When you wrap a copper wire around a nail and run an electric current through the wire, you create an electromagnetic field. How does the amount of copper wire affect the force field?

Answer explanation

The more copper wire wrapped around the nail, the stronger the magnetic field.

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5

What does a magnetic field tell us about two magnets placed side by side?

Answer explanation

By looking at the field lines, you can tell if the magnets are aligned at the top with north pole and north pole, or if you have north pole and south pole at the top of the two magnets.

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5

Students want to investigate how the amount of electric energy delivered to a motor affects its speed. Which of the following procedures will most likely produce the data students need to answer their question?

• Connect a series of motors to the same battery to figure out how
      many motors can be run off the same battery

• Closely observe the rotation of the motor to see if the direction of spin
      reverses when the poles of the battery are switched.

• Measure the rotations per second of a motor when it is connected to
      one battery, two batteries, and three batteries.

• Add larger and larger motors to a battery to determine the size of the
      largest motor the battery is able to run.

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-5

The table provided shows data collected by students during an investigation of two electromagnets. Which of the following conclusions is supported by data on the table?

• Electromagnets that repel each other have more force than those that attract each other.

• The greater the charges of two electromagnets, the greater the size of the force.

• When two electromagnets are of like charges, they attract each other.

• If the charge on one magnet is positive, the charge on the other must be negative.

Tags

NGSS.MS-PS2-3

The illustration shows a hand generator. Turning the handle of the generator spins a magnet and creates an electric current that lights the bulb. Which of the following observations can be used to indicate the strength of the current created by the generator?

• The size of the magnet

• The length of the handle

• The mass of the generator

• The brightness of the bulb

Match the following:

• Charged object

• The tendency to push other objects away from it

• Magnitude

• The tendency to pull other objects toward it

• Repulsive

• A directional flow of electric charge

• Current

• The size of something

• Attraction

• Matter with a surplus of electrons

When two ​ (a)   charged metal objects are pushed closer together, their repulsive force ​ (b)   . ​ (c)   objects exert forces on each other. When magnetic poles that are ​ (d)   align, they will have an attractive force. When the currents of two electromagnets are increased, the size of the ​ (e)   is increased.

• alike
• increases
• charged
• opposites
• force
• positively
• negatively
• greater
• decreases
• magnet

Tags

NGSS.MS-PS2-3

NGSS.MS-PS2-5