A2 Magnetic fields

A _______________ is a current-carrying coil of wire with many loops

• electromagnet
• solenoid
• magnet
• compass

The strength of a magnet can be changed by

• adding less loops to the coil.
• adding more loops to the coil.

The strength of an electromagnet can be affected by

• changing the current in the wire
• changing the space between the wires
• all of the above
• none of the above

An example of the best insulator is

• copper
• salt
• plastic
• sand

An example of a good conductor is

• copper
• sand
• plastic

Electrical insulators have _________ resistance to the movement of electrons.

• high
• low
• no

The coil of current-carrying wire with an iron core is called a(n)

• ferromagnet
• electromagnet
• compass
• maglev

An electromagnet is a solenoid with an __________ core.

• copper
• wire
• iron

Which of the following best describes this picture?

• Pipes and stuff
• Magnet
• Electromagnet
• Resistor

This is a picture of a simple electromagnet. How can the electromagnet be made stronger?

• Add more coils of wire to the nail.
• Use a smaller battery.
• Reverse the poles of the magnet.
• Remove all the coils and the nail.