P7 Magnetism and Electromagnetism

Question 1

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

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

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

Answer 11

solenoid

Question 12

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

Answer 12

inside the coil

Question 13

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

Answer 13

strong and uniform

Question 14

What is an electromagnet?

Answer 14

A solenoid containing an iron core which increases its strength

Question 15

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

Answer 15

can be switched on and off with electric current

Question 16

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

Answer 16

Force, magnetic field and current

Question 17

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

Answer 17

Force

Question 18

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

Answer 18

Current

Question 19

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

Answer 19

Magnetic Field

Question 20

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

Answer 20

exert an equal and opposit force on one another

Question 21

Give three ways of increasing the force of a solenoid.

Answer 21

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

Question 22

Give three ways of increasing the force of a motor.

Answer 22

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

Question 23

What is the unit of magnetic flux density?

Answer 23

Tesla (T)

Question 24

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

Answer 24

Iron filings or plotting compass

Question 25

The right hand thumb rule shows relative direction of…

Answer 25

current and magnetic field around a wire

Question 26

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

Answer 26

Size of current and distance from wire

Question 27

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

Answer 27

F=BIl

Question 28

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

Answer 28

Flemming’s left hand rule.