Physics- electricity and magnetism

Topic 1

What is a magnetic material?

A material that attracts to a magnetic field

What are non-magnetic materials?

Materials that don’t attract to a magnetic fields

What are poles?

The two ends of a magnet

What is magnetically hard?

Substances that can be permanently magnetised

What is magnetically soft?

Substances that can only be magnetised temporarily

What does a magnetic field do?

Fills the space around a magnet

What describes the magnetic force at every point in space?

A magnetic field

How can we visualise a magnetic field?

Using magnetic field lines

What do magnetic field lines show?

The shape of the field,the direction of the force, the strength of the magnetic field

What direction dies the magnetic force go in?

North to south

How can the magnetic field lines of a bar magnet be traced out?

Using a compass.

What is the needle of the compass?

A permanent magnet and the north indicator of the compass

What can electricity hazards cause?

Overheating or electric shock

How can we reduce these hazard?

Using appropriate insulation, using appropriate fuses/circuit breakers or earthing the component

What is a fuse?

A thin piece of wire

What happens if too large a current flows in the circuit with a fuse there?

The fuse gets very hot and melts

How does having the fuse reduce electrical hazards?

Reduces the chance of an electrical fire

What are the most common fuses made of?

Metal

What is the correct fuse?

One that allows the correct current to flow but breaks if the current is a little longer

What does p stand for?

Power in watts

What does i stand for?

Current in amps

What does v stand for ?

Voltage in volts

What is the equation using p,i and v?

P = i x v

What is current?

The flow of charged particles

Which ways do the flow of electrons go in current?

Negative to positive

What is voltage measured in?

Volts

What is voltage?

The average of the difference in electric energy between two parts of a circuit

Do magnetic fields lines cross?

No

What does resistance do?

Restricts the flow of current

What is resistance opposite to?

Current flow in an electrical circuit

What is resistance caused by?

Electrical collisions with ions and transferring energy

What happens when electrons collide with ions in the metal?

They transfer energy ions vibrate more

What happens as the temperature increases and the ions vibrate more?

Collisions become more frequent

What increases the resistance of the conductor?

The collisions becoming more frequent

What is power?

How much energy is transferred in 1s

What is power measured in?

Watts or joules per second

What is the equation using e,i,v and t

E =I x V x T

What is the equation using e,p and t

E =P x T

What is the equation using p,i,v?

P = I x V

What is E measured in?

J

What is I measured in?

A

What is V measured in?

V

What is t measured in?

S

What is j?

Joules