P7 Magnetism and Electromagnetism Flashcards Preview

PHYSICS Questions > P7 Magnetism and Electromagnetism > Flashcards

Flashcards in P7 Magnetism and Electromagnetism Deck (28)
Loading flashcards...
1
Q

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

A

poles

2
Q

What is the definition of a magnetic field?

A

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

3
Q

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

A

Magnetic field

4
Q

Two like poles always ______

A

repel

5
Q

Tow opposite poles always _______

A

attract

6
Q

What is a permanent magnet?

A

A magnet that produces its own magnetic field.

7
Q

What is an induced magnet?

A

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

8
Q

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

A

induced magnet

9
Q

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

A

induced magnet

10
Q

Which three elements are magnetic?

A

iron, cobalt and nickel

11
Q

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

A

solenoid

12
Q

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

A

inside the coil

13
Q

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

A

strong and uniform

14
Q

What is an electromagnet?

A

A solenoid containing an iron core which increases its strength

15
Q

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

A

can be switched on and off with electric current

16
Q

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

A

Force, magnetic field and current

17
Q

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

A

Force

18
Q

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

A

Current

19
Q

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

A

Magnetic Field

20
Q

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

A

exert an equal and opposit force on one another

21
Q

Give three ways of increasing the force of a solenoid.

A

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

22
Q

Give three ways of increasing the force of a motor.

A

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

23
Q

What is the unit of magnetic flux density?

A

Tesla (T)

24
Q

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

A

Iron filings or plotting compass

25
Q

The right hand thumb rule shows relative direction of…

A

current and magnetic field around a wire

26
Q

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

A

Size of current and distance from wire

27
Q

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

A

F=BIl

28
Q

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

A

Flemming’s left hand rule.