OCR PHYSICS A LEVEL PAPER 2 EXAM WITH
VERIFIED QUESTIONS AND ANSWERS||
GUARANTEED PASS|| LATEST VERSION 2026
What is the atomic structure of a metal? - ANSWER-A lattice of positive ions
surrounded by a sea of free electrons.
What is a photoelectron? - ANSWER-An electron that has been removed from a
metal by absorbing a photon
What is the work function? - ANSWER-The minimum energy required to
remove an electron from the surface of a metal
What is the threshold frequency? - ANSWER-The minimum frequency of light
required to produce photoelectrons from a metal
What is monochromatic light - ANSWER-Light of a single
frequency/wavelength
What is the relationship between work function and threshold frequency? -
ANSWER-∅ = hf₀
What is required for a photon to be able to produce photoelectrons? -
ANSWER-Its frequency is greater than the threshold frequency
Why can't light sources below the threshold frequency produce photoelectrons?
- ANSWER-The photon energy is less than the work function
,How do photons and electrons interact? - ANSWER-A single photon can be
absorbed/emitted by a single electron which gains/loses the energy of the
photon.
What is the effect on an electron of absorbing a photon? - ANSWER-The
electron gains the energy of the photon
What effect does increasing the frequency of a monochromatic light source
have on photoelectrons produced? - ANSWER-Photoelectrons will have a
greater maximum kinetic energy
What is the quark composition of a neutron? - ANSWER-up down down (udd)
What is the quark composition of a proton? - ANSWER-up up down (uud)
What is the quark composition of an anti-baryon? - ANSWER-Three antiquarks
Name the two types of hadron. - ANSWER-baryons and mesons
What force hold quarks together in hadrons? - ANSWER-The strong nuclear
force.
What is the family of particles that are subject to both the strong and weak
nuclear force? - ANSWER-Hadrons
What type of particle are nucleons? - ANSWER-Baryons
,How does a proton compare to an antiproton? - ANSWER-The have the same
mass but opposite charge.
How does an electron compare to a positron? - ANSWER-The have the same
mass but opposite charge.
What is the antiparticle of the electron? - ANSWER-Positron.
What is I in the equation I = I₀e^(-µx)? - ANSWER-Transmitted intensity
What is I₀ in the equation I = I₀e^(-µx)? - ANSWER-Intensity before absorption
What is µ in the equation I = I₀e^(-µx)? - ANSWER-Attenuation/absorption
coefficient.
What is x in the equation I = I₀e^(-µx)? - ANSWER-Thickness of the absorbing
substance
What are the SI units of attenuation coefficient? - ANSWER-m⁻¹
What is a contrast medium in X-rays? - ANSWER-A material with a high
attenuation coefficient used to image soft tissue.
What contrast medium is typically to examine blood flow? - ANSWER-Iodine
What contrast medium is typically used to image the digestive system? -
ANSWER-Barium sulfate
How are X-rays used for cancer therapy? - ANSWER-A linear accelerator
produces high energy X-rays that destroy cells.
, Why are high energy X-rays prefereable to gamma radiation for cancer therapy?
- ANSWER-An X-ray source can be turned off.
What is X-ray attenuation? - ANSWER-The decrease in intensity as X-rays pass
through matter.
What are the four mechanisms of X-ray attenuation? - ANSWER-Simple
scatter, Photoelectric Effect, Compton Scattering, Pair Production
What occurs during simple scatter of X-rays? - ANSWER-The X-ray interacts
with an electron in an atom and changes direction but not energy.
Which method of attenuation is most significant with X-rays with energy in the
range 1-20keV? - ANSWER-Simple scatter
What occurs during the photoelectric effect attenuation of X-rays? - ANSWER-
The X-ray is absorbed by an electron in an atom which gains the energy of the
photon and leaves the atom.
Which method of attenuation is significant with X-rays with energies up to
100keV? - ANSWER-Photoelectric effect
Which method of attenuation is most significant to medical X-ray imaging? -
ANSWER-The photoelectric effect.
What type of particle are there millions of passing through your body every
second? - ANSWER-Neutrinos
Describe beta minus decay. - ANSWER-A neutron in an unstable nucleus
decays into a proton and emits an electron and an antineutrino.
VERIFIED QUESTIONS AND ANSWERS||
GUARANTEED PASS|| LATEST VERSION 2026
What is the atomic structure of a metal? - ANSWER-A lattice of positive ions
surrounded by a sea of free electrons.
What is a photoelectron? - ANSWER-An electron that has been removed from a
metal by absorbing a photon
What is the work function? - ANSWER-The minimum energy required to
remove an electron from the surface of a metal
What is the threshold frequency? - ANSWER-The minimum frequency of light
required to produce photoelectrons from a metal
What is monochromatic light - ANSWER-Light of a single
frequency/wavelength
What is the relationship between work function and threshold frequency? -
ANSWER-∅ = hf₀
What is required for a photon to be able to produce photoelectrons? -
ANSWER-Its frequency is greater than the threshold frequency
Why can't light sources below the threshold frequency produce photoelectrons?
- ANSWER-The photon energy is less than the work function
,How do photons and electrons interact? - ANSWER-A single photon can be
absorbed/emitted by a single electron which gains/loses the energy of the
photon.
What is the effect on an electron of absorbing a photon? - ANSWER-The
electron gains the energy of the photon
What effect does increasing the frequency of a monochromatic light source
have on photoelectrons produced? - ANSWER-Photoelectrons will have a
greater maximum kinetic energy
What is the quark composition of a neutron? - ANSWER-up down down (udd)
What is the quark composition of a proton? - ANSWER-up up down (uud)
What is the quark composition of an anti-baryon? - ANSWER-Three antiquarks
Name the two types of hadron. - ANSWER-baryons and mesons
What force hold quarks together in hadrons? - ANSWER-The strong nuclear
force.
What is the family of particles that are subject to both the strong and weak
nuclear force? - ANSWER-Hadrons
What type of particle are nucleons? - ANSWER-Baryons
,How does a proton compare to an antiproton? - ANSWER-The have the same
mass but opposite charge.
How does an electron compare to a positron? - ANSWER-The have the same
mass but opposite charge.
What is the antiparticle of the electron? - ANSWER-Positron.
What is I in the equation I = I₀e^(-µx)? - ANSWER-Transmitted intensity
What is I₀ in the equation I = I₀e^(-µx)? - ANSWER-Intensity before absorption
What is µ in the equation I = I₀e^(-µx)? - ANSWER-Attenuation/absorption
coefficient.
What is x in the equation I = I₀e^(-µx)? - ANSWER-Thickness of the absorbing
substance
What are the SI units of attenuation coefficient? - ANSWER-m⁻¹
What is a contrast medium in X-rays? - ANSWER-A material with a high
attenuation coefficient used to image soft tissue.
What contrast medium is typically to examine blood flow? - ANSWER-Iodine
What contrast medium is typically used to image the digestive system? -
ANSWER-Barium sulfate
How are X-rays used for cancer therapy? - ANSWER-A linear accelerator
produces high energy X-rays that destroy cells.
, Why are high energy X-rays prefereable to gamma radiation for cancer therapy?
- ANSWER-An X-ray source can be turned off.
What is X-ray attenuation? - ANSWER-The decrease in intensity as X-rays pass
through matter.
What are the four mechanisms of X-ray attenuation? - ANSWER-Simple
scatter, Photoelectric Effect, Compton Scattering, Pair Production
What occurs during simple scatter of X-rays? - ANSWER-The X-ray interacts
with an electron in an atom and changes direction but not energy.
Which method of attenuation is most significant with X-rays with energy in the
range 1-20keV? - ANSWER-Simple scatter
What occurs during the photoelectric effect attenuation of X-rays? - ANSWER-
The X-ray is absorbed by an electron in an atom which gains the energy of the
photon and leaves the atom.
Which method of attenuation is significant with X-rays with energies up to
100keV? - ANSWER-Photoelectric effect
Which method of attenuation is most significant to medical X-ray imaging? -
ANSWER-The photoelectric effect.
What type of particle are there millions of passing through your body every
second? - ANSWER-Neutrinos
Describe beta minus decay. - ANSWER-A neutron in an unstable nucleus
decays into a proton and emits an electron and an antineutrino.
