AS Physics – Module 1

Definitions

For each term, think of a definition.

After 15 seconds, the definition will appear

…as if by magic!

Then play the ppt again and see how many you can remember

Current

“The rate of flow of charge”

Potential Difference

“The energy transferred when unit charge passes between two points”

1 Volt =

“1 Volt = 1 Joule/Coulomb”

Resistance

“R=V/I”

Ohm’s Law

“Current is proportional to p.d. provided temperature remains constant”

Current Electricity

Power“Rate of energy transfer”Kirchoff’s First Law“Conservation of charge – at any junction the algebraic sum of

the currents is zero”Kirchoff’s Second Law“Conservation of energy – the algebraic sum of potential

differences around a closed circuit is zero”EMF“The energy transferred to unit charge as it passes through a

cell”Or “The p.d. across the source when no current flows”Internal Resistance“Energy transferred within a cell as charge flows through it”

Current Electricity

Peak Value“Maximum displacement from the zero line, labelled either I0

or V0”Peak to Peak Value“Maximum displacement across both directions (+ and -) Time Period“Time for one complete cycle, T”Frequency“Number of cycles (waves) per second, measured in Hertz”root mean square value“The effective d.c. value that would produce the same

heating effect in a resistor”

Current Electricity

Proton“Positive constituent of an atom’s nucleus”Neutron“Neutral constituent of an atom’s nucleus”Electron“Negatively charged particle orbiting the nucleus”Atomic number or Proton number“Number of protons in the nucleus (also equal to number of electrons)”Nucleon number or Mass number“Number of protons and neutrons in an atom’s nucleus”Isotope“A form of an element with the same proton number but different

neutron number”

Particles

Antimatter“Mirror image of a particle with identical mass but opposite

charge and other quantum properties”Annihilation“Conversion of mass to energy – particle and antiparticle are

converted into a pair of photons”Pair Production“A high energy photon is converted into a pair of particles”

Particles

Strong Force“Force experienced by hadrons (baryons and mesons)”Weak Force“Force experienced by leptons and hadrons, responsible for

changes to quark composition”Electromagnetic Force“Force experienced by charged particles”Gravity“Force experienced by all particles with mass”

Particles

Fundamental Particles“Can’t be broken down into smaller particles: Leptons are

fundamental”Leptons“Electron, muon, tau, (Q=-1 for all), electron neutrino, muon

neutrino, tau neutrino and their anti-particles)Hadrons“Baryons: 3 quarks, Antibaryons: 3 antiquarks, mesons: quark

and an anti-quark”

Particles

Photoelectric EffectElectrons are emitted from the surface of a metal when the

frequency of light is above a threshold valueThreshold FrequencyThe minimum frequency of light needed to cause emission of an

electron from a metalWork FunctionThe energy needed to remove an electron from the surface of a

metalElectronvoltAmount of energy gained by an electron accelerated through a

p.d. of 1VoltExcitationElectron moves up an energy levelIonisationElectron becomes free from the atom

Particles

Wave-Particle DualityThe ability for waves to behave like particles and particles to

behave like wavesWave nature of particlesElectron DiffractionParticle nature of wavesPhotoelectric effectdeBroglie WavelengthA particle of momentum p should have an associated wavelength

λ

Particles