Which material is a composite?(1 point)
Responses
gold
gold
aluminum
aluminum
silicon
silicon
polycarbonate
polycarbonate
What happens to some metals when the kinetic energy of their particles is decreased?(1 point)
Responses
They conduct.
They conduct.
They melt.
They melt.
They expand.
They expand.
They contract.
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.
Yes, it would. Aluminum is a conductor, and the glass would prevent electricity from transferring to a person holding the device.
Yes, it would. Aluminum is a conductor, and the glass would prevent electricity from transferring to a person holding the device.
Which material would be a suitable insulator?(1 point)
Responses
rubber
rubber
gold
gold
silver
silver
copper
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
carbon steel
carbon steel
gold
gold
copper
copper
iron