Conductors and Insulators

A material that lets electricity pass through it is called ...

• an electrical conductor
• an electrical insulator
• an electrical appliance

A material that does NOT let electricity pass through it is called ...

• an electrical conductor
• an electrical insulator
• an electrical appliance

Which of the following materials is an electrical conductor?

• silver
• silver-colored plastic
• cork
• rubber

Which of the following materials is an electrical insulator?

• aluminum
• gold
• rubber
• steel

In which circuit will the bulb or bulbs glow brightest?

• A simple circuit with one bulb and one battery
• A simple circuit with one bulb and two batteries
• A simple circuit with two bulbs and one battery

Why is a bulb brighter when it is powered by two batteries rather than one?

• Because the flow of electricity in the circuit is less
• Because the flow of electricity in the circuit is the same
• Because the flow of electricity in the circuit is greater

Ruby has connected two bulbs across two batteries in a series circuit. How can she make the bulbs dimmer?

• Replace one of the batteries with a section of wire
• Replace one of the batteries with a cork
• Replace one of the bulbs with a section of wire

Ruby makes a complete simple circuit with one bulb and three batteries. The bulb lights for an instant and then goes out. Why?

• Not enough electricity flows around the circuit
• Too much electricity flows through the bulb's filament
• The batteries are dead

Why is electrical wiring usually made from copper?

• Because copper is shiny
• Because copper conducts electricity
• Because copper is not magnetic

Why is electrical wiring usually covered with a layer of plastic?

• To help electricity flow along the wire
• To make it look pretty
• To make it safe