Gravitational vs Magnetic vs electric field Review

A student claims that Earth has a magnetic field. Which evidence would best support the student's claim?

• The student creates a working circuit that illuminates a bulb using wire and a battery.

• The student turns in all directions with a compass and the needle always points north.

• The student receives a shock after walking across the carpet and touching a doorknob.

• The student rolls a ball down a large hill and the ball comes to a complete stop at the bottom

Cameron and Morgan are each holding a bar magnet with opposite poles facing each other. They walk in opposite directions until they stop feeling their magnet pull towards the other one. What can they conclude about the distance between them when they stop feeling their magnets pull?

• They are outside the magnetic field of their magnets.

• The distance made the magnets' force stronger.

• The magnetic fields are far enough apart to change direction.

• The magnetic field was weaker when they were close.

Ivan has a magnet and four different objects. He places the magnet near each of the objects and records whether each object attracts, repels, or has no reaction. Which question is Ivan's experiment designed to answer?

• Which type of magnet will apply force on an object?

• How can magnetic force affect an object's shape?

• Which objects will respond to a magnetic force?

• How does an object's gravity affect a magnet?

If two charges attract to each other, then which of the following is true?

• Both charges must be positive.

• Both charges must be negative

• Both charges must be different.

• Both charges must be equal in value.

A student claims that the magnetic fields are not the same across the magnet. Using the picture, what evidence best supports the claim?

• The magnetic fields of the magnet are strongest at both poles.

• The magnetic fields of the magnet are strongest at the north pole.

• The magnetic fields of the magnet are strongest at the south pole.

• The magnetic fields of the magnet are strongest at the middle

A student claims that the gravitational force between two objects depends upon the mass of the objects and the distance between them. Which argument best supports the student's claim?

• If the distance between two objects increases, the gravitational force between the objects will decrease.

• If the distance between two objects decreases, the gravitational force between the objects will disappear.

• If the distance between two objects increases, the gravitational force between the objects will increase.

• If the distance between two objects decreases, the gravitational force between the objects will not change.

Bob and Suzy are designing an electromagnet. Bob wants to add another battery to make the magnet stronger, and Suzy wants to add more coils to make the magnet stronger. Who is correct?

• Bob

• Suzy

• Neither Bob nor Suzy

• Both Bob and Suzy

Which choice below shows a difference between gravitational fields, electrical fields, and magnetic fields?

• Gravitational fields are invisible, electrical and magnetic fields are visible.

• Gravitational fields can attract and repel, electrical and magnetic fields cannot.

• Gravitational fields involve positive and negative charges, electrical and magnetic fields involve poles.

• Gravitational fields can only attract, electrical and magnetic fields can both attract and repel.

At which point is the electric field the weakest?

• A because it is the furthest away
• A because the field lines are further apart
• C because the field lines are further apart
• C  because it is the furthest away

Consider the electric field lines shown in the diagram below. From the diagram, it is apparent that object A is ____ and object B is ____.

• +,+
• +,-
• -,+
• -,-