IGCSE Physics Electric Charge

The diagram shows a balloon hanging from an insulating thread. A student gives the balloon a positive charge. Which statement explains why the balloon becomes positively charged?

• the balloon gains electrons

• the balloon loses electrons

• the balloon gains protons

• the balloon loses protons

A student rubs a plastic rod with a dry cloth, as shown in the diagram. The rod becomes negatively charged. The student moves the rod close to a suspended, charged rod. The two rods repel each other. Why?

• They have the same charge.

• They have opposite charges.

• They are both made of plastic.

• They are both insulators.

A plastic ruler is given a positive charge. A sphere hangs from an insulating thread. A student holds the ruler near the sphere, as shown in the diagram. The ruler repels the sphere. State what charge, if any, the sphere carries.

• Negative charge.

• Neutral charge.

• Positive charge.

• No charge.

Describe what is meant by an electric field.

• A region where there is a magnet.

• A region where there is electricity.

• A region in which an electric charge experiences a force.

• A region where there could be electricity.

Three balls P, Q and R are electrically charged. The balls are suspended by threads of insulating

material. The diagram shows the arrangement. Ball P is negatively charged. State the charge on ball Q.

• positively charged

• negatively charged

• neutrally charged

• no charge

A positively-charged rod is held near to, but not touching, an uncharged metal sphere. The sphere is briefly now connected to earth. The rod is removed. Which statement about the charge on the sphere is correct?

• It is charged negatively because negative charges have moved from earth to the sphere.

• It is charged negatively because positive charges have moved from the sphere to earth.

• It is charged positively because negative charges have moved from the sphere to earth.

• It is charged positively because positive charges have moved to earth from the sphere.

Which of the following is a/are good conductor(s)?

• gold

• copper

• iron

• polystyrene

Which of the following is a/are good insulator(s)?

• plastic

• cotton

• polythene

• silver