A LEVEL PHYSICS AQA EXAM 2025
QUESTIONS AND ANSWERS
Vector - ANS A quantity that has magnitude and direction
Absolute Zero - ANS Lowest possible temperature, 0K, object has minimum internal energy.
Scalar - ANS A quantity that only has magnitude
Acceleration - ANS Change of velocity per unit time.
free body diagram - ANS a diagram showing all the forces acting on an object
Activity of a Radioactive Isotope - ANS Number of nuclei of the isotope that disintegrate per
second.
Energy: scalar or vector? - ANS scalar
Becquerel (Bq) - ANS Unit of radioactive activity, 1Bq = 1 disintegration per second.
Acceleration: scalar or vector? - ANS vector
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,Amplitude - ANS Maximum displacement from equilibrium of oscillating object.
Displacement (scalar or vector) - ANS vector
Angular Displacement - ANS Angle an object in circular motion turns through in radians.
𝜃 = 𝜔t
Speed: scalar or vector? - ANS scalar
Angular Speed (ω) - ANS Rate of change of angular displacement of object in circular motion.
𝜔 = 2𝜋f
Annihilation - ANS When a *particle and its antiparticle meet*, they destroy each other to
*produce 2 photons of equal energy*.
Here the minimum energy of each photon produced = hf(min) = rest energy of the particle.
Antiparticle - ANS *Equal rest mass* and *equal and opposite charge* to particle.
Atomic Number, Z - ANS Number of *protons* in nucleus of atom.
Avogadro Constant - ANS The *number of atoms in 12g of carbon-12*. Used to define the
mole.
Back emf - ANS The emf induced in the spinning coil of electric motor or in any coil in which
the current is changing. A back emf acts against the change of applied pd.
Background Radiation - ANS *Radiation due to naturally occurring substances* in the
environment e.g. radon gas, cosmic rays, ground and buildings.
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,Binding Energy - ANS *Work done* to separate a nucleus into its *constituent nucleons*
(neutrons and protons).
E = mass defect x c²
Binding Energy per Nucleon - ANS Average work done per nucleon to separate nucleus into
constituent parts. Higher the value, the more stable the nucleus.
*BE per nucleon = BE of a nucleus / mass number*.
Boyle's Law - ANS For a *fixed mass of gas* at a *constant temperature*, its *pressure x
volume is constant*. Gases that obey this are an ideal gas.
Boltzmann Constant (k) - ANS Molar gas constant divided by Avogadro number.
Brittle - ANS Snaps without stretching or bending when subject to stress.
Brownian Motion - ANS *Random and unpredictable motion of a particle* eg. smoke
particles caused by molecules of the surrounding substance colliding with it. Provided evidence
for existence of atom.
Capacitance - ANS The *charge stored per unit pd of a capacitor*. Unit is Farad (F) equal to 1
coulomb per volt. Q = CV.
Centre of Mass - ANS Point through which a single force on the body has no turning effect.
Centripetal Force - ANS Resultant force on an object that moves along a circular path. Acts
towards centre of circle.
F = mv²/r = m𝜔²r
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, Chain Reaction - ANS Series of reactions in which each reaction causes a further reaction e.g.
nuclear fission. Steady reaction where on average one neutron from each fission event goes on
to cause a further fission event.
Charge Carriers - ANS Charged particles that move through a substance when a pd is applied
across it.
Charles' Law - ANS For a *fixed mass* of an ideal gas at a *constant pressure*, volume is
directly proportional to its absolute temperature
Coherent - ANS Two sources of waves emitted with a constant phase difference.
Conservation of Momentum - ANS Total momentum of objects in system remains constant
provided no external force acts on system.
Control Rods - ANS Made of *neutron absorbing* materials such as *cadmium* or *boron*.
Moved in and out of reactor core to change rate of fission events to ensure it is *constant*.
Coolant - ANS Pumped through nuclear reactor core to transfer thermal energy from core to
turn turbine.
Count Rate - ANS Number of counts per unit time detected by a Geiger-Muller tube.
*Corrected by subtracting background count rate*.
Couple - ANS Pair of equal and opposite forces acting on a body but not along the same line.
Critical Angle - ANS Angle of incidence of light ray must exceed the critical angle for total
internal reflection to occur.
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QUESTIONS AND ANSWERS
Vector - ANS A quantity that has magnitude and direction
Absolute Zero - ANS Lowest possible temperature, 0K, object has minimum internal energy.
Scalar - ANS A quantity that only has magnitude
Acceleration - ANS Change of velocity per unit time.
free body diagram - ANS a diagram showing all the forces acting on an object
Activity of a Radioactive Isotope - ANS Number of nuclei of the isotope that disintegrate per
second.
Energy: scalar or vector? - ANS scalar
Becquerel (Bq) - ANS Unit of radioactive activity, 1Bq = 1 disintegration per second.
Acceleration: scalar or vector? - ANS vector
Copyright ©2025 BRIGHTSTARS ALL RIGHTS RESERVED 1
,Amplitude - ANS Maximum displacement from equilibrium of oscillating object.
Displacement (scalar or vector) - ANS vector
Angular Displacement - ANS Angle an object in circular motion turns through in radians.
𝜃 = 𝜔t
Speed: scalar or vector? - ANS scalar
Angular Speed (ω) - ANS Rate of change of angular displacement of object in circular motion.
𝜔 = 2𝜋f
Annihilation - ANS When a *particle and its antiparticle meet*, they destroy each other to
*produce 2 photons of equal energy*.
Here the minimum energy of each photon produced = hf(min) = rest energy of the particle.
Antiparticle - ANS *Equal rest mass* and *equal and opposite charge* to particle.
Atomic Number, Z - ANS Number of *protons* in nucleus of atom.
Avogadro Constant - ANS The *number of atoms in 12g of carbon-12*. Used to define the
mole.
Back emf - ANS The emf induced in the spinning coil of electric motor or in any coil in which
the current is changing. A back emf acts against the change of applied pd.
Background Radiation - ANS *Radiation due to naturally occurring substances* in the
environment e.g. radon gas, cosmic rays, ground and buildings.
Copyright ©2025 BRIGHTSTARS ALL RIGHTS RESERVED 2
,Binding Energy - ANS *Work done* to separate a nucleus into its *constituent nucleons*
(neutrons and protons).
E = mass defect x c²
Binding Energy per Nucleon - ANS Average work done per nucleon to separate nucleus into
constituent parts. Higher the value, the more stable the nucleus.
*BE per nucleon = BE of a nucleus / mass number*.
Boyle's Law - ANS For a *fixed mass of gas* at a *constant temperature*, its *pressure x
volume is constant*. Gases that obey this are an ideal gas.
Boltzmann Constant (k) - ANS Molar gas constant divided by Avogadro number.
Brittle - ANS Snaps without stretching or bending when subject to stress.
Brownian Motion - ANS *Random and unpredictable motion of a particle* eg. smoke
particles caused by molecules of the surrounding substance colliding with it. Provided evidence
for existence of atom.
Capacitance - ANS The *charge stored per unit pd of a capacitor*. Unit is Farad (F) equal to 1
coulomb per volt. Q = CV.
Centre of Mass - ANS Point through which a single force on the body has no turning effect.
Centripetal Force - ANS Resultant force on an object that moves along a circular path. Acts
towards centre of circle.
F = mv²/r = m𝜔²r
Copyright ©2025 BRIGHTSTARS ALL RIGHTS RESERVED 3
, Chain Reaction - ANS Series of reactions in which each reaction causes a further reaction e.g.
nuclear fission. Steady reaction where on average one neutron from each fission event goes on
to cause a further fission event.
Charge Carriers - ANS Charged particles that move through a substance when a pd is applied
across it.
Charles' Law - ANS For a *fixed mass* of an ideal gas at a *constant pressure*, volume is
directly proportional to its absolute temperature
Coherent - ANS Two sources of waves emitted with a constant phase difference.
Conservation of Momentum - ANS Total momentum of objects in system remains constant
provided no external force acts on system.
Control Rods - ANS Made of *neutron absorbing* materials such as *cadmium* or *boron*.
Moved in and out of reactor core to change rate of fission events to ensure it is *constant*.
Coolant - ANS Pumped through nuclear reactor core to transfer thermal energy from core to
turn turbine.
Count Rate - ANS Number of counts per unit time detected by a Geiger-Muller tube.
*Corrected by subtracting background count rate*.
Couple - ANS Pair of equal and opposite forces acting on a body but not along the same line.
Critical Angle - ANS Angle of incidence of light ray must exceed the critical angle for total
internal reflection to occur.
Copyright ©2025 BRIGHTSTARS ALL RIGHTS RESERVED 4
