Year 12: All 3 marks
Explain, with reference to a progressive
wave on a string, how a standing wave
pattern forms
Explain how a stationary wave pattern
is set up
Explain in terms of forces why an object
reaches terminal velocity
Use the ideas of path/phase difference
to explain why an interference pattern
forms
Explain the pattern of dark and light
fringes for light that passes through a
single slit
Explain the variation of intensity when
two loudspeakers play the same note
simultanouesly
Explain the shape of a V-I graph for a
filament bulb
State and explain how the current in a
circuit changes when a thermistor is
heated
State and explain how the voltmeter
reading changes as intensity of light on
an LDR increases
Explain how braking distance of a car
depends on initial speed
Explain why the p.d. in a circuit does
not equal the emf
Explain how the photoelectric effect is
evidence of photons
Explain how to use an oscilloscope to
measure the time period of a sound
wave
Explain advantages of using a
datalogger
Year 13: all 3 marksheme
Explain how Brownian motion
provides evidence of molecules
Describe the life cycle of a star like
the sun
Explain why the potential energy of
an electron in an atom is negative
Describe the motion of electrons in
a circuit with a capacitor when the
switch is closed
Describe how transformers induce
an emf in the secondary coil
Describe evidence for the Big Bang
theory / why cosmic background
radiation is evidence of the Big
Bang theory
movement of smoke particles caused by (being hit by) randomly moving air
molecules
smoke particles are continuously moving because the air molecules are
continuously moving
smoke particles are visible but air molecules are not hence air molecules
must be (very) small.
small movement of smoke particles is due to the large numbers of air
molecules hitting from all sides
Gas / dust (cloud) drawn together by gravitational forces
Loss in (gravitational) PE -> temperature increase
Fusion of hydrogen nuclei (produces helium nuclei and energy)
A stable star is formed when radiation pressure is equal to gravitational
pressure
When hydrogen runs out the outer layers of the star expands / core shrinks
Red giant formed / eventually (the core becomes) a white dwarf
Potential energy of electron is 0 at an infinite distance from atom
Work is done moving the electron closer to the atom
so the electron loses potential energy
Electrons leave the battery’s negative terminal and….
Build up on the plate closest to the negative terminal…
And repel electrons from the other plate which…
Flow to the positive terminal of the battery
Alternating p.d. in the primary coil creates a….
Changing magnetic field through iron core which…
Induces an alternating p.d. in the secondary coil
Shift in wavelength from galaxies towards the red end of spectrum (red
shift) as universe expanded
Further galaxies are receding at faster rate (so were closer together
previously)
Cosmic microwave background radiation (gamma rays present at Big Bang
stretched as universe expanded)
Explain how emission spectra form
Explain how the scattering of alpha
particles by gold foil is evidence of
the nuclear model of the atom
Describe and explain the
conditions required for nuclear
fusion in the sun’s core
Hydrogen nuclei need to be close enough to overcome electrostatic
repulsion and allow strong force to act
High density / pressure forces nuclei closer
High temperatures allow fast moving nuclei to get close so strong
(nuclear) force overcomes electrostatic repulsion
Describe the phenomena of
resonance
• Resonance occurs when the driving frequency matches natural /
resonant frequency (of system) • the amplitude of vibrations / energy
(transferred) is then a maximum (AW)
Electrical – affect charges; attractive and repulsive; long range 1/r2
Gravitational – affect masses; attractive; long range 1/r2
Compare and contrast electrical
fields and gravitational fields
Compare and contrast capacitor
discharge and nuclear decay
Capacitor – exponential; charge on plates decreases; can control rate of
discharge (R,C)
Nuclear – exponential; number of undecayed nuclei decreases; can’t
control rate of decay
Explain how the graph shows the
system has exponential decay
Explain how the graph shows the
system has simple harmonic
motion
Explain the processes that control
the stages of a star lifecycle
Exponential – constant ratio (in the same time interval, the original value
drops by same proportion)
SHM – graph of a against x is straight line through origin (acceleration
proportional to displacement); negative gradient as a always directed
towards centre