Electricity, Magnetism, Gravity (Mid-Term Review 2019)

Why is copper classified as a conductor?

• Electric current travels easily through copper.
• Copper may gain or lose electric charges.
• Copper resists the flow of electrical current.
• None of the other answer choices

Why are the wires in electric circuits often coated with plastic?

• The plastic carries the electric current.
• The plastic keeps the electric current inside the wire.  
• The plastic allows the wire to bend into different shapes.
• The plastic acts as a switch to turn the electric current on or off.  

Which set of materials could be used to make an electromagnet?

• A D-cell battery, a box of paper clips, and a switch
• A bar magnet, a copper wire, and a light bulb
• A bar magnet, a spool of electrical wire, and an electrical outlet
• An iron nail, a spool of electrical wire, and a D-cell battery

What makes a material a good conductor?

• A conductor makes it difficult for electricity to flow through it.
• A conductor allows electricity to flow through it.
• A conductor transforms electrical energy into other forms of energy.
• None of the other answer choices

Which of the following best describes an electromagnet?

• A magnet created when electric current flows through wire coiled around an
  iron bar
• A magnet created when wire is wrapped around an iron bar
• A magnet that is attracted to anything with an electric current
• None of the other answer choices

Catalina wants to make an electromagnet using materials she already has. She plans to wrap the middle of a long piece of wire around an object and then connect the ends of the wire to a battery. Which of the following would be the best object for her to wrap with the wire?

• A rolled-up newspaper
• A plastic bottle
• An iron screw
• A glass jar

Which is one way to increase the strength of an electromagnet?

• Coil the wire around an aluminum core
• Add more coils of wire
• Decrease the amount of electric current
• Remove some coils of wire

Tags

NGSS.MS-PS2-3

Which of the following is a true statement about the magnetic field between two magnets?

• 
  The south pole of one magnet is attracted to the south pole of the other magnet.
• The north pole of one magnet is attracted to the north pole of the other magnet.
• 
  The south pole of one magnet is attracted to the north pole of the other magnet.
• 
  The south pole of one magnet is attracted to both poles of the other magnet.

What device is used to create electricity?

• resistor
• insulator
• voltmeter
• generator

Laundry in a clothes dryer often become charged with static electricity while drying. Which of these best explains why a clothes dryer often generates static electricity?

• heat from the dryer charges the air and produces lightning
• 
  electrons are transferred as clothes rub against each other in the dryer
• short circuits in the dryer charge the laundry
• clothes with metal pieces conduct electricity in the dryer