Class resources

 

Derivation of Resistivity formula:
 
p = RA/L          R prop L       R prop 1/A       R prop R/A
 
R = p(L/A)       R = pL/A       p = RA / L.
 
 
Proof of monochromatic light formula
 
 
Proof of F = qVB
 
The Wheatstone bridge explained:
 

The transformer explained:

 
The Milikan oil drop experiment explained
 
Why is ionising radiation considered dangerous?
The radiations from radioactive materials – alpha, beta and gamma radiation – are all ionising radiations which can damage living cells. Ionising radiation can break molecules into smaller fragments. ... This may result in the living cells dying or becoming cancerous. Radiation can also affect DNA, causing mutations.
When atoms in living cells become ionized one of three things usually happen – the cell dies, the cell repairs itself, or the cell mutates incorrectly and can become cancerous. Not all cells are affected by ionizing radiation in the same way.
If the radioactive source is outside the body: alpha radiation is not as dangerousbecause it is unlikely to reach living cells inside the body. beta and gamma radiationare the most dangerous sources because they can penetrate the skin and damage the cells inside.
 
 
Explanation of harmonics in pipes:
 
 
Ray Diagrams Lenses
Specific latent heat table

 
Guide to students on how to build free websites and what to look out for:
 
Article to guide you around website builders advantages and pitfalls.
 
Top 10 free website builders Link
 
You tube video presentations on building free websites.