Electromagnetic InductionCutting a wire through a

magnetic field induces a p.d.

If a current is induced (need a circuit) this is the DYNAMO EFFECT

We can increase the voltage by:

• moving the wire quicker

• having a stronger magnetic field;

• using a coil of wire consisting of more turns or a larger area

Wire 1

Magnetic field lines going into screen

Solenoid

Transformers

Only work using alternating current (a.c.)

a.c. in primary coil induces a magnetic field.

Magnetic field induces a p.d in the secondary coil

p.d. across primary  = number of turns on primary     p.d. across secondary  number of turns on secondary 

Vp = NpVs    Ns

2400 turns

Primary Coil

240 turns

Secondary Coil

Transformers and the National Grid

Power stationStep up

transformerStep down

transformerHomes

Increases voltage

Decreases voltage

High voltage = low current so less energy lost

Low voltage = high current

Can use in homes safely

Radiation

Quarks and electrons (~0.1s)

Neutrons and protons (~100s)

Hydrogen (H) and Helium (He) (~100,000 years)

Galaxies and stars (~few billion years)

Galaxies

GR

AV

ITY D

ID IT!!

!

Evidence:

Redshift

CMB

How the chemical elements formed

Hydrogen to heliumHelium to heavier

elements up to iron

Too much energy is needed to make heavier elements in a star.

To make heavier elements need a supernova!

Deuterium

Tritium

Helium

+

Neutron

Force of Gravity

Force of Explosion

Nuclear fusion

Foundation Paper

Question 2

Question 3

Question 4