26. Radiation is the emission of particles of matter or photons of energy.
27. Background radiation is radiation that comes from environmental sources including the Earth’s crust, the atmosphere, cosmic rays and radioisotopes.
Particle Physics (Option 1)
1. Neutrinos are subatomic particles that are produced in beta decay; they have very little mass and are electrically neutral.
2. Antimatter is matter composed of antiparticles; antiparticles are subatomic particles of matter that are identical to another subatomic particle in mass but opposite to it in electric charge.
3. The positron is the antiparticle of the electron.
4. Pair production is the formation of one electron and one positron from a gamma photon.
5. Pair annihilation is the formation of two photons when a particle–antiparticle pair collide; the pair convert all their mass into energy.
6. Leptons are indivisible point objects that are not subject to the strong force.
7. Hadrons are subatomic particles that experience all the fundamental forces, including the strong nuclear force.
8. Baryons are hadrons that are made from any combination of three quarks or three antiquarks.
9. Mesons are hadrons that are made from any quark–antiquark pair. 10. Quarks are fundamental building blocks of baryons and mesons.
Applied Electricity (Option 2)
1. An electromagnetic relay is an electromechanical switch made up of an electro- magnet and a set of contacts.
2. Electromagnetic induction is where an emf is induced by a change in the magnetic flux linking a circuit.
3. An induction coil is an electronic device used to get a very high voltage from a low voltage d.c. source.
4. Rectification is the conversion of alternating current to direct current.
5. An LED (light-emitting diode) is a semiconductor device that emits light when current flows through it.
6. A photodiode is a semiconductor device used to detect the presence of light or to measure its intensity, or as part of a light sensitive relay.
7. A transistor is a semiconductor device, with three terminals, which can act as a switch, a (voltage or current) amplifier, a voltage inverter or a NOT logic gate.
8. A logic gate is an electronic circuit used to calculate operations in Boolean algebra.
