CRASHCOURSE QUIZ BLOCK 4

The forces between magnetic poles and between magnets and magnetic materials can be described using the terms north pole (N pole), south pole (S pole), attraction, repulsion, magnetised, and unmagnetised. Which statement best describes these forces?

• Like poles repel and unlike poles attract; magnets attract magnetic materials by inducing magnetism in them.

• Like poles attract and unlike poles repel; magnets repel all magnetic materials.

• Only north poles attract magnetic materials; south poles have no effect.

• Magnets can only attract other magnets, not magnetic materials.

Induced magnetism is best described as:

• The process by which a material becomes magnetic when placed in a magnetic field.

• The permanent magnetism found in all metals.

• The loss of magnetism when heated.

• The ability of a magnet to attract only non-metallic objects.

Which of the following correctly states the difference between the properties of temporary magnets (made of soft iron) and permanent magnets (made of steel)?

• Temporary magnets made of soft iron lose their magnetism easily, while permanent magnets made of steel retain their magnetism for a long time.

• Temporary magnets made of soft iron retain their magnetism for a long time, while permanent magnets made of steel lose their magnetism easily.

• Both temporary magnets and permanent magnets retain their magnetism for the same duration.

• Temporary magnets made of steel lose their magnetism easily, while permanent magnets made of soft iron retain their magnetism for a long time.

The difference between magnetic and non-magnetic materials is that:

• Magnetic materials are attracted to magnets, while non-magnetic materials are not.

• Non-magnetic materials are always metals, while magnetic materials are always non-metals.

• Magnetic materials cannot conduct electricity, while non-magnetic materials can.

• Non-magnetic materials are attracted to magnets, while magnetic materials are not.

A magnetic field is a region in which a magnetic pole experiences a force.

• True

• False

• Only near electric charges

• Only inside a magnet

The pattern and direction of magnetic field lines around a bar magnet are:

• Emerge from the north pole and enter the south pole outside the magnet

• Emerge from the south pole and enter the north pole outside the magnet

• Form straight lines between the poles

• Are randomly oriented around the magnet

State that the direction of a magnetic field at a point is the direction of the force on the N pole of a magnet at that point.

• The direction of a magnetic field at a point is the direction of the force on the N pole of a magnet at that point.

• The direction of a magnetic field at a point is the direction of the force on the S pole of a magnet at that point.

• The direction of a magnetic field at a point is always towards the center of the magnet.

• The direction of a magnetic field at a point is perpendicular to the force on the N pole of a magnet at that point.

The plotting of magnetic field lines can be done using a compass or iron filings, and a compass is used to determine the direction of the magnetic field. Which of the following best describes this process?

• A compass aligns itself with the magnetic field, and iron filings reveal the pattern of the field lines.

• A compass creates magnetic field lines, and iron filings measure their strength.

• Iron filings generate a magnetic field, and a compass measures its temperature.

• A compass and iron filings both block the magnetic field lines.

Permanent magnets and electromagnets are used for which of the following purposes?

• Permanent magnets are used in compasses and speakers, while electromagnets are used in electric bells and cranes.

• Permanent magnets are only used in electric bells, while electromagnets are used in compasses.

• Permanent magnets and electromagnets are both used only in toys.

• Permanent magnets are used in cranes, while electromagnets are used in compasses.

Magnetic forces are due to interactions between:

• magnetic fields

• electric currents only

• gravitational fields

• sound waves