U4 C2

Object 1 is given a negative charge and placed on a balance.

Object 2, which is also charged, is brought close to object 1 and the reading on the balance changes as shown.

Which action would further decrease the reading on the balance?

• Add the same number of electrons to both objects.

• Remove the same number of electrons from both objects.

• Transfer electrons from object 1 to object 2.

• Transfer electrons from object 2 to object 1.

In the diagram, rod R is suspended from an insulating thread.

When the positively charged rod Q is brought close to rod R, rod R moves away from rod Q.

Which conclusion can be made from this observation?

• Rod R is charged, but it is not possible to identify the sign of the charge.

• Rod R must be positively charged.

• Rod R must be negatively charged.

• Rod R is uncharged.

A teacher wishes to show the production of electrostatic charges.

She holds a rod and rubs it with a cotton cloth. A copper rod, a glass rod, a plastic rod and a steel

rod are available.

Which two rods would both be suitable to use?

• a copper rod and a glass rod

• a glass rod and a plastic rod

• a plastic rod and a copper rod

• a plastic rod and a steel rod

A plastic rod is rubbed with a cloth.

The rod and the cloth both become charged as electrons move between them.

The rod becomes negatively charged.

Which diagram shows how the rod becomes negatively charged and shows the final charge on the cloth?

• A

• B

• C

• D

A plastic rod is rubbed with a dry cloth. The rod becomes positively charged.

Why has the rod become positively charged?

• It has gained electrons.

• It has gained neutrons.

• It has lost electrons.

• It has lost neutrons.

A plastic rod and a dry cloth are uncharged.

The rod is now rubbed with the cloth and they both become charged. The rod becomes negatively charged because some charged particles move from the cloth to the rod.

What is the charge on the cloth and which particles moved in the charging process?

• A

• B

• C

• D

A man walks across a carpet. He becomes negatively charged by friction with the carpet.

What happens as he touches a metal object connected to the Earth?

• The man gains electrons.

• The man loses electrons.

• The man gains protons.

• The man loses protons.

A negatively charged plastic rod P is placed above a positively charged plastic rod Q.

 

What are the directions of the electrostatic forces on rod P and on rod Q?

• A

• B

• C

• D

A plastic rod is rubbed with a dry woollen cloth. The rod becomes positively charged.

Which statement is correct?

• Electrons move from the cloth to the rod.

• Electrons move from the rod to the cloth.

• Protons move from the cloth to the rod.

• Protons move from the rod to the cloth.

The diagram shows a charged plastic rod and an uncharged metal sphere. The metal sphere is suspended by an insulating thread.

The plastic rod is then moved close to the metal sphere.

Which row is correct?

• A

• B

• C

• D