Charges

Two balls are placed near one another and hang down, as shown below.

Which conclusion is supported by this evidence?

• Neither ball has a charge.

• The balls are both positively charged.

• One ball is positively charged, and the other is negatively charged.

• Each ball has a charge, but the type of charge is unknown.

A negatively charged rod is placed near two neutral metal spheres, as shown below.

Which statements describe the charging method shown? Check all that apply.

• The spheres develop opposite charges.

• The spheres develop the same charge.

• Electrons move from Sphere A to Sphere B.

• The spheres are charged through conduction.

• The spheres are charged through induction.

The diagram shows two charged objects, X and Y.

Based on the field lines, what are the charges of the objects?

• X: positive

  Y: negative

• X: negative

  Y: positive

• X: negative

  Y: negative

• X: positive

  Y: positive

Which change increases the electric force between objects?

• Two neutral objects are moved closer together.

• Electrons are added to two negatively charged objects.

• Two oppositely charged objects are moved farther apart.

• The charge on two positively charged objects is reduced.

How does increasing the distance between charged objects affect the electric force between them?

• The electric force increases because the distance has an indirect relationship to the force.

• The electric force increases because the distance has a direct relationship to the force.

• The electric force decreases because the distance has an indirect relationship to the force.

• The electric force decreases because the distance has a direct relationship to the force.

A plastic rod becomes negatively charged when it is rubbed with a piece of wool. How does the rod become charged?

• Electrons move from the rod to the wool.

• Protons move from the rod to the wool.

• Electrons move from the wool to the rod.

• Protons move from the wool to the rod.

Hiro rubs an inflated balloon on his hair, and his hair sticks to the balloon. As he moves the balloon away from his head, how does the electric force change?

• The electric force increases because the balloon loses its charge.

• The electric force increases because the distance increases.

• The electric force decreases because the distance increases.

• The electric force decreases because his hair loses its charge.

Tisa makes a diagram to organize her notes about charging objects.

Which statement should she place in the region marked X?

• Electrons move between objects.

• The objects do not touch.

• The objects develop opposite charges.

• The objects have the same charge.

The image shows the electric field lines around two charged particles.

At which position would the electric force be greatest?

• 1

• 2

• 3

• 4

A small, positively charged ball is moved close to a large, positively charged ball. Which describes how the small ball likely responds when it is released?

• It will move toward the large ball because like charges repel.

• It will move toward the large ball because like charges attract.

• It will move away from the large ball because like charges repel.

• It will move away from the large ball because like charges attract.