P7-Magnetism And Electromagnetism

Question 1

Alternator (H)

Answer 1

A device that makes use of the generator effect to generate alternating current (H)

Question 2

Attraction

Answer 2

Opposite poles will experience a force of attraction, meaning they will experience a force towards each other. The force between a magnet and magnetic material is always one of attraction.

Question 3

Current-Carrying Wires

Answer 3

When current flows through a wire, a magnetic field is generated around it. The strength of the field is dependent on the magnitude of the current and the distance from the wire

Question 4

Dynamo (H)

Answer 4

A device that makes use of the generator effect to generate direct current. (H)

Question 5

Electric Motor (H)

Answer 5

A current-carrying coil of wire in a magnetic field. The two sides of the coil that are perpendicular to the magnetic field experience forces in opposite directions, causing rotation (H)

Question 6

Electromagnet

Answer 6

A solenoid with an iron core

Question 7

Fleming’s Left-Hand Rule (H)

Answer 7

A rule used to determine the orientation of the force (thumb), current (second finger) and magnetic field (first finger) when a current carrying wire is placed in a magnetic field (motor effect) (H)

Question 8

Generator Effect (H)

Answer 8

When there is relative motion between an electrical conductor and a magnetic field, a potential difference will be induced across the ends of the conductor. A current will flow if this conductor is part of a complete circuit (H)

Question 9

Induced Magnet

Answer 9

A material that becomes a magnet when it is placed in an existing magnetic field, but loses its magnetism quickly once it is removed. Induced magnetism always produces attractive forces

Question 10

Magnetic Compass

Answer 10

A device containing a small bar magnet that points in the direction of the Earth’s magnetic field.

Question 11

Magnetic Field Lines

Answer 11

Lines representing the strength and direction of a magnetic field. The field line direction at any point is in the direction that a force would act on another north pole if placed at that point

Question 12

Magnetic Field

Answer 12

The region around a magnet in which another magnet or magnetic material will experience a force.

Question 13

Magnetic Materials

Answer 13

Iron, steel, cobalt and nickel

Question 14

Magnetic Poles

Answer 14

The regions of a magnet where the magnetic forces are at their strongest.

Question 15

Microphone (H)

Answer 15

A device that uses the generator effect to convert the pressure variations of sound waves into variations in the electrical current of a circuit. (H)

Question 16

Motor Effect (H)

Answer 16

When a current-carrying wire is placed in a magnetic field, a force will be experienced between the wire and the magnet responsible for the field. (H)

Question 17

Permanent Magnet

Answer 17

A magnet that produces its own magnetic field

Question 18

Repulsion

Answer 18

Like-poles will experience a force of repulsion, meaning they will experience forces in opposite directions.

Question 19

Solenoid

Answer 19

A wire wrapped into the shape of a coil, that has a strong and uniform magnetic field inside of it. The solenoid’s magnetic field strength can be increased by adding an iron core

Question 20

Step-Down Transformer (H)

Answer 20

A transformer that has a smaller potential difference in the secondary coil than in the primary core. (H)

Question 21

Step-Up Transformer (H)

Answer 21

A transformer that has a larger potential difference in the secondary coil than in the primary core. (H)

Question 22

Tesla

Answer 22

The unit of magnetic flux density.

Question 23

Transformer (H)

Answer 23

An iron core with a primary and secondary coil of wire wound around opposite ends. (H)