0625 P4 Electricity and Magnetism

What are the forces between magnetic poles and between magnets and magnetic materials?

• Only attraction

• Only repulsion

• Both attraction and repulsion

• Neither attraction nor repulsion

What is the term used to describe the process by which a material becomes magnetized when placed in a magnetic field?

• Permanent magnetism

• Induced magnetism

• Electromagnetism

• Temporary magnetism

What is the difference between temporary magnets and permanent magnets?

• Temporary magnets are made of soft iron, and permanent magnets are made of steel.

• Temporary magnets must be induced by an electric current, permanent magnets must be induced by the Earth's magnetic field

What is a magnetic field?

• A region where a magnetic pole experiences a force

• A region where there is no magnetic force

• A region where only electric forces are present

• A region where gravitational forces are present

What is the direction of a magnetic field at a point?

• The direction of the force on the S pole of a magnet at that point

• The direction of the force on the N pole of a magnet at that point

• The direction of the force on the E pole of a magnet at that point

• The direction of the force on the W pole of a magnet at that point

What is the use of a compass in plotting magnetic field lines?

• To measure the strength of the magnetic field

• To determine the direction of the magnetic field

• To create a magnetic field

• To demagnetize a material

What are the uses of permanent magnets and electromagnets?

• Permanent magnets are used in computers and on fridges, whereas electromagnets are used in relays and transformers.

• Permanent magnets are used in speakers and door locks, whereas electromagnets are used in scrap yards and MRI machines.

What causes magnetic forces?

• Interactions between electric fields

• Interactions between gravitational fields

• Interactions between magnetic fields

• Interactions between nuclear fields

How is the relative strength of a magnetic field represented?

• By the color of the magnetic field lines

• By the length of the magnetic field lines

• By the spacing of the magnetic field lines

• By the thickness of the magnetic field lines

What type(s) of electric charge are there?

• There are only positive charges.

• There are only negative charges.

• There are positive and negative charges.

• There are north and south poles.