Which material is a composite?(1 point)
Responses
gold
gold
polycarbonate
polycarbonate
silicon
silicon
aluminum
polycarbonate
What happens to some metals when the kinetic energy of their particles is decreased?(1 point)
Responses
They contract.
They contract.
They expand.
They expand.
They melt.
They melt.
They conduct.
They contract.
Aluminum allows for the flow of electrons, while glass does not. Would an aluminum wire surrounded by glass be an effective design for a device that will need to carry an electric current?(1 point)
Responses
Yes, it would. The glass would carry the current, while aluminum is an insulator.
Yes, it would. The glass would carry the current, while aluminum is an insulator.
No, it would not. Both aluminum and glass are insulators, so the device would not carry a current.
No, it would not. Both aluminum and glass are insulators, so the device would not carry a current.
No, it would not. Both aluminum and glass are conductors, so the current would be exposed to outside elements.
No, it would not. Both aluminum and glass are conductors, so the current would be exposed to outside elements.
Yes, it would. Aluminum is a conductor, and the glass would prevent electricity from transferring to a person holding the device.
No, it would not. Both aluminum and glass are insulators, so the device would not carry a current.
Which material would be a suitable insulator?(1 point)
Responses
silver
silver
copper
copper
rubber
rubber
gold
rubber
An electrician is trying to decide which kind of material to use to wire a house.
carbon steel: conductivity = 1.43 × 10−7, resistance = 1 × 1010
copper: conductivity = 5.96 × 107, resistance = 1.68 × 10-8
gold: conductivity = 4.11 × 107, resistance = 2.44 × 10−8
iron: conductivity = 1 × 107, resistance = 1.0 × 10−7
Based on this information, which material should the electrician use?
(1 point)
Responses
copper
copper
iron
iron
carbon steel
carbon steel
gold