Paper 2 Magnetism & Electromagnetism

Question 1

What are permanent magnets?

Answer 1

Permanent magnets

PRODUCE THEIR OWN MAGNETIC FIELD

Question 2

What are Induced Magnets?

Answer 2

Induced magnets

BECOME a magnet when placed in a MAGNETIC FIELD

When removed from the magnetic field, they LOSE THEIR MAGNETISM quickly

Question 3

What do like pole do?

Answer 3

Like poles - REPEL

(The north pole of a magnet will REPEL (push away) a north pole

A south pole will REPEL another south pole)

Question 4

UNLIKE POLES …..

Answer 4

Unlike Poles … ATTRACT

The north pole of a magnet will attract the south pole of another magnet

Question 5

What does it mean when the FIELD LINES around a magnet are drawn CLOSED TOGETHER?

Answer 5

Field lines show closed together mean … that the strength of a magnet is STRONG

Question 6

There are 2 types of magnetic poles

Answer 6

Magnetic poles -

NORTH seeking & SOUTH seeking poles

Question 7

What is a magnetic field?

Answer 7

Magnetic Field is:

the REGION around a magnet where force acts on another magnet/magnetic material

Question 8

Name magnetic materials:

Answer 8

Magnetic materials

.  Magnets
.  Iron
.  Steel
.  Nickel
.   Cobalt

Question 9

Where is the magnetic field strongest?

Answer 9

The Magnetic Field is strongest at: THE POLES

Question 10

What is the FLUX DENSITY?

Answer 10

The Flux Density is:

. The density (THE THICKNESS) of the magnetic field lines

. It indicates the STRENGTH of the FIELD

. The CLOSER the lines - the HIGHER the flux density - the SRONGER the field & the GREATER force that would be felt by another magnet

Question 11

Field lines run in which direction?

Answer 11

The field lines run from NORTH to SOUTH

Question 12

The strength of a magnetic field depends on:

Answer 12

The strength of a magnetic field depends on:

. the SIZE of the CURRENT & the DISTANCE from the WIRE

Question 13

What is a SOLENOID?

Answer 13

A Solenoid is when:

. a WIRE is LOOPED into a CYLINDRICAL COIL
. the LOOP INCREASES the strength of the MAGNETIC FIELD
. AN IRON CORE can be added to create a STRONGER FIELD … this is called an ELECTROMAGNET

Question 14

Why does a SOLENOID increase the magnetic field:

Answer 14

The SOLENOID increases the magnetic field because:

. It concentrated a LONGER piece of WIRE into a smaller area

. the LOOPED shape means that the magnetic field lines are ALL in the SAME DIRECTION

. strong UNIFORM field inside the SOLENOID

Question 15

How can the north pole of a SOLENOID be found?

Answer 15

The north pole of a SOLENOID can be found by:

. THE RIGHT HAND GRIP METHOD

Question 16

An example of an ELECTROMAGNETIC DEVICE

Answer 16

An Electromagnetic device -

Electric Bell …

. Push the switch - the ELECTROMAGNET is MAGNETISED

Question 17

What does the Force (N) depend on:

Answer 17

The FORCE depends on:

. Magnetic Flux DENSITY (T)

. Current (A)

. Length (m)

Question 18

The force (A) equals

Answer 18

Force (N) = B x I x l

force = magnetic flux density (T) current (A) length (m)

Question 19

When would you use FLEMING’s LEFT HAND RULE?

Answer 19

FLEMING’S LEFT hand rule is used to find:

the FORCE on the conductor

Thumb = Movement (direction of force)

First finger = Field (magnetic field)

Second = Current (direction of current)

Question 20

What do we use the motor effect for?

Answer 20

The motor effect is used:

In MOTORS to CONVERT ELECTRICAL ENERGY into KINETIC ENERGY

Question 21

What happens if the conductor is parallel to the the magnetic field?

Answer 21

If the conductor is parallel to the magnetic field it will NOT EXPERIENCE A FORCE

Question 22

Advantages of an ELECTROMAGNET?

Answer 22

An Electromagnet can:

. Be switches on and off - so it can pick up a car then release it.

. A permanent magnetic cannot be switches on and off

Question 23

Electromagnetic radiation wave lengths:

Answer 23

Radio waves 1500 m

Visible light 5 x 10 -7m

Ultraviolet wave 3 x 10- 8m

X-rays - 1 x 10 -11m