CP10 Electromagnetism

Question 1

The places on a magnet where the magnetic forces are the strongest are called the…

Answer 1

poles

Question 2

What is the definition of a magnetic field?

Answer 2

The area around a magnet where a force acts on another magnet or magnetic material

Question 3

The area around a magnet where a force acts on another magnet or magnetic material in the…

Answer 3

Magnetic field

Question 4

Two like poles always ______

Answer 4

repel

Question 5

Tow opposite poles always _______

Answer 5

attract

Question 6

What is a permanent magnet?

Answer 6

A magnet that produces its own magnetic field.

Question 7

What is an induced magnet?

Answer 7

A magnetic material which becomes a magnet when placed in a magnetic field.

Question 8

A magnetic material which becomes a magnet when placed in a magnetic field is a _______ _________

Answer 8

induced magnet

Question 9

What type of magnet loses its magnetism when it is removed from a magnetic field?

Answer 9

induced magnet

Question 10

Which three elements are magnetic?

Answer 10

iron, cobalt and nickel

Question 11

Draw the magnetic field around a bar magnet

Answer 11

teacher to draw on board…

Question 12

Give the name for the magnet created using a coil of wire

Answer 12

solenoid

Question 13

Where is the strongest field in an electromganet created by a coil of wire?

Answer 13

inside the coil

Question 14

What two words describe the magnetic field within the coil of a solenoid?

Answer 14

strong and uniform

Question 15

What is a uniform magnetic field?

Answer 15

One that is the same direction and strength everywhere.

(shown by equally spaced straight lines on a diagram)

Question 16

What is an electromagnet?

Answer 16

A solenoid containing an iron core which increases its strength

Question 17

What is an important property of a solenoid/electromagnet as a magnet

Answer 17

can be switched on and off with electric current

Question 18

Flemming’s left hand rule shows the relative directions of what things?

Answer 18

Force, magnetic field and current

Question 19

In Flemming’s LH rule, the thumb gives the direction of …

Answer 19

Force

Question 20

In Flemming’s LH rule, the second finger gives the direction of …

Answer 20

Current

Question 21

In Flemming’s LH rule, the first finger gives the direction of …

Answer 21

Magnetic Field

Question 22

When a conductor carrying a current is placed in a magnetic field, the magnet and the conductor ….

Answer 22

exert an equal and opposit force on one another

Question 23

Give three ways of increasing the force of a solenoid.

Answer 23

Add iron core, increase number of coils of wire, increase current, move magnetic material closer

Question 24

Give three ways of increasing the force of a motor.

Answer 24

Increase the number of coils of wire, increase the strength of the magnetic field, increase the current

Question 25

What is the unit of magnetic flux density?

Answer 25

Tesla (T)

Question 26

What two methods can you use to obesrve the field around a bar magnet?

Answer 26

Iron filings or plotting compass

Question 27

Draw the magnetic field between two like poles.

Answer 27

teacher to draw on board…

Question 28

Draw the magnetic field between two unlike poles.

Answer 28

teacher to draw on board…

Question 29

The right hand thumb rule shows relative direction of…

Answer 29

current and magnetic field around a wire

Question 30

The strength of magnetic field surrounding a conducting wire depends on…

Answer 30

Size of current and distance from wire

Question 31

State the equation which links current, force, length of conductor and magnetic flux density

Answer 31

F=BIl

Question 32

Which rule can be used to determine the direction a motor will rotate?

Answer 32

Flemming's left hand rule.

Question 33

What does a basic transformer consist of?

Answer 33

A primary coil and a secondary coil wound on an iron core.

Question 34

Why is iron used as the core of a transformer?

Answer 34

It is easily magnetised.

Question 35

What is the purpose of a transformer?

Answer 35

To change the size of the potential difference of an alternating current

Question 36

What does a step up transformer do?

Answer 36

Increases the potential difference of an alternating current

Question 37

What type of current does a transformer require?

Answer 37

A.C. Alternating Current

Question 38

What is electromagnetic induction?

Answer 38

The induction of a potential difference in a wire which is experiencing a change in magnetic field