2.5 Electromagnetism

The interaction between electricity and magnetism has been an important topic in 20th century science. Which term describes this interaction?

• electromagnetism
• ferromagnetic
• magnetic field
• static electricity

What is the best word to describe a system in which a magnet moves in a coil of wire to produce electricity?

• electromagnet
• generator
• motor
• transformer

Which of the following best describes how a powerful electromagnet could be used in a junkyard?

• It could move heavy objects made of iron.
• It could convert electrical energy into mechanical energy.
• It could light up the area so workers can see at night.
• It could provide a voltage source for old electronic equipment.

Daniel has a long piece of copper wire. He shapes the wire into a coil. What could Daniel do to cause electric current to flow through the wire?

• shake the wire very quickly
• submerge the wire into a pan of hot water
• move a bar magent in and out of the wire coil
• connect the two free ends of the wire so that they form a closed path

Which devices directly use electromagnetism to function?

• a magnet and a battery
• a galvanometer and a generator
• a wire and a magnet
• a loop of wire and a generator

Which of the following describes the most likely application of electromagnetism in a power plant?

• Magnets detect the presence of electric currents in nature.
• Magnets covert electric energy into mechanical energy.
• Moving a magnet in a coil of wire generates an electric current.
• Moving a magnet in a coil of wire produces visible light.

Which of the following is the best definition of electromagnetism?

• the use of electricity to create magnets
• the use of magnets to generate electricity
• the interaction between electricity and magnetism
• the appearance in nature of objects that have both electric and magnetic fields

Which phenomenon is most directly responsible for Earth's magnetic field?

• Earth's rotation about its axis
• Earth's revolution around the sun
• the moon's revolution around Earth
• the moon's gravitational pull on Earth

A(n) _________ is coil of wire that produces a magnetic field when it carries an electric current.

• generator
• magnetic field
• solenoid
• primary side

A(n)_________ changes mechanical energy into electrical energy by means of electromagnetic induction.

• a domain
• generator
• solenoid
• magnetic pole