Electricity And Magnestism

Question 1

Atoms

Answer 1

Everything us made of particles called atoms. Their charge is neutral.

Question 2

What are atoms made of.

Answer 2

Protons - positive charge
Electrons - negative charge
Neutrons - no charge

Question 3

Attraction and repelling

Answer 3

Like charges repel and unlike charges attract.

Question 4

Static electricity

Answer 4

When two objects are rubbed together, electrons are transferred from one object to another.

Question 5

Current electricity

Answer 5

From the flow of electrons along a conductor.

Question 6

Electric field

Answer 6

Is a region where there is a force on charged particles or materials.

Question 7

Electric current

Answer 7

It is the amount of charge flowing per second. You measure it in amps (A) with an ammeter.

Question 8

Potential difference

Answer 8

The potential difference of a cell (battery) tells you the size of the push on the charges and how much energy can be transferred by them.

Question 9

How do you measure potential difference.

Answer 9

It is measured in volts (V) using a voltmeter. The rating of a cell or battery tells you the potential difference at which it operates..

Question 10

What is a series circuit?

Answer 10

It contains only one loop and the current is the same everwhere.

Question 11

What is a parallel circuit?

Answer 11

A parallel circuit has multiple branches and the current in the branches add up to make the total current.

Question 12

Potential difference - series circuit

Answer 12

The potential difference across each component adds up to the potential difference across the battery.

Question 13

Potential difference - parallel circuit

Answer 13

The potential difference across each component is the same as the potential difference across the battery.

Question 14

Resistance

Answer 14

A component with a hugh resistance has a small current running thorugh it.

Question 15

Insulator

Answer 15

Has a high resistance to current eg plastics

Question 16

Conductor

Answer 16

Conductors have a low resistance to current eg metals.

Question 17

How do you calculate resistance.

Answer 17

Resistance is measured in ohms.

You calculate resistance = potential difference (voltage) \current (A)

Question 18

What do magnets have?

Answer 18

They have a north and south pole.

Like poles repel and unlike poles attract.

Question 19

What are the 4 magnetic materials?

Answer 19

Iron, cobalt, nickel and steel.

Question 20

Magnetic field

Answer 20

Magnetic materials feel a force in the region around a magnet called a magnetic material.
Magnetic field lines show the pattern of a magnetic field. They run from the north pole to south pole.

Question 21

How do you find magnetic field lines?

Answer 21

You can see the field with a small compass or iron filings.

If the lines are closer together the field is stronger.

Question 22

What is an electromagnet?

Answer 22

A current flowing in a coil of wire wrapped around a magnetic material is an electromagnet. They are only magnetic when they have a flow of current, so they can be turned on and off.

Question 23

Electromagnets have what in their centre?

Answer 23

They usually have an iron core in the middle which makes them stronger.

Question 24

How do I make an electromagnet stronger?

Answer 24

Adding more loops/turns in the coil.
Using more current.
The type of core.
You can make electromagnets much stronger than permanent magnets.

Question 25

What are the uses of electromagnets?

Answer 25

Moving cars or other metal objects (scrap yard)
Sorting iron and steel from aluminium.
Making motors and speakers.
Making levitating trains, which travel much faster as there is no friction.

Question 26

How do motors work?

Answer 26

Applying a current to a coil of wire makes it electromagnetic.
This causes a force between the coil of wire and the permanent magnet nearby, driving a motor.