BDA RADIOGRAPHY AND RADIOLOGY EXAM
PREP STUDY GUIDE 2 2026 PRACTICE
QUESTIONS AND SOLUTIONS GRADED A+
◉ What is the difference between X-rays and gamma rays? Answer:
Gamma rays are naturally occurring, while X-rays are man-made.
◉ What are the four main ways X-ray photons can interact with
matter? Answer: 1. Transmission - pass through matter without
interaction. 2. Absorption - all energy is absorbed by matter.
3. Absorption and Scatter - deflected with energy loss.
4. Pure Scatter - deflected with no energy loss.
◉ What are tissue reaction effects in the context of ionising
radiation? Answer: Tissue reaction effects (somatic, deterministic
effects) result from high doses of radiation, where the severity of
damage is proportional to the dose.
◉ What are stochastic effects of ionising radiation? Answer:
Stochastic effects are chance effects that can occur from any dose of
radiation, with severity not related to the dose. A single X-ray photon
can potentially cause fatal cancer.
,◉ What is the main aim of radiation protection in dental
radiography? Answer: To completely prevent deterministic effects
and limit the chances of stochastic effects to an acceptable level.
◉ What is the nature of X-rays? Answer: X-rays are packets of energy
called photons that travel in straight lines and can travel in a
vacuum.
◉ How do X-rays interact with film emulsion? Answer: X-rays can
blacken film emulsion to create an image.
◉ What is the significance of the phrase 'there is no such thing as a
safe dose of radiation'? Answer: It emphasizes that any exposure to
radiation carries some level of risk.
◉ What are the characteristics of X-ray photons? Answer: X-ray
photons have a short wavelength and high energy, originating and
interacting at the atomic level.
◉ What are the genetic effects of ionising radiation? Answer:
Genetic effects occur in reproductive cells (egg and sperm) and may
affect future offspring.
,◉ What is the relationship between radiation dose and stochastic
effects? Answer: Increasing the radiation dose increases the chance
of stochastic damage occurring.
◉ What is the significance of the term 'ionising radiation'? Answer:
Ionising radiation has enough energy to remove tightly bound
electrons from atoms, which can lead to tissue damage.
◉ What is the potential risk associated with a single X-ray photon?
Answer: Although very unlikely, it has the potential to cause fatal
cancer.
◉ What is the role of physical methods in radiation protection?
Answer: Physical methods are used to reduce the level of risk
involved with radiation exposure.
◉ What is the nature of photons in the electromagnetic spectrum?
Answer: Photons come in a wide range of energies, with very low
energy making up radio waves and medium energy visible as light.
◉ What is the importance of understanding atomic interactions in X-
ray production? Answer: Understanding atomic interactions is
crucial for explaining how X-rays are produced.
, ◉ What are the basic features of dental X-ray generating equipment?
Answer: Dental X-ray equipment includes components like the
tubehead, X-ray tube, step-up transformer, oil for heat removal, and
a spacer cone for aiming the beam.
◉ What is the relevance of current recommendations and
regulations concerning X-ray equipment? Answer: Regulations
ensure safety and effectiveness in X-ray usage, including
specifications for equipment design, operation, and exposure limits.
◉ How do exposure variables kV, mA, and time affect dental X-ray
images? Answer: kV controls the energy and penetrating power of X-
ray photons; mA and time control the quantity of X-ray photons
produced, affecting film blackening.
◉ What is the effect of increasing kV on the contrast of a
radiographic image? Answer: Increasing kV decreases the contrast
between light and dark parts of the radiographic image, summarized
as 'kV kills contrast'.
◉ What happens to low-energy X-ray photons in the body? Answer:
Low-energy X-ray photons tend to be absorbed by soft tissues, which
can cause damage.
PREP STUDY GUIDE 2 2026 PRACTICE
QUESTIONS AND SOLUTIONS GRADED A+
◉ What is the difference between X-rays and gamma rays? Answer:
Gamma rays are naturally occurring, while X-rays are man-made.
◉ What are the four main ways X-ray photons can interact with
matter? Answer: 1. Transmission - pass through matter without
interaction. 2. Absorption - all energy is absorbed by matter.
3. Absorption and Scatter - deflected with energy loss.
4. Pure Scatter - deflected with no energy loss.
◉ What are tissue reaction effects in the context of ionising
radiation? Answer: Tissue reaction effects (somatic, deterministic
effects) result from high doses of radiation, where the severity of
damage is proportional to the dose.
◉ What are stochastic effects of ionising radiation? Answer:
Stochastic effects are chance effects that can occur from any dose of
radiation, with severity not related to the dose. A single X-ray photon
can potentially cause fatal cancer.
,◉ What is the main aim of radiation protection in dental
radiography? Answer: To completely prevent deterministic effects
and limit the chances of stochastic effects to an acceptable level.
◉ What is the nature of X-rays? Answer: X-rays are packets of energy
called photons that travel in straight lines and can travel in a
vacuum.
◉ How do X-rays interact with film emulsion? Answer: X-rays can
blacken film emulsion to create an image.
◉ What is the significance of the phrase 'there is no such thing as a
safe dose of radiation'? Answer: It emphasizes that any exposure to
radiation carries some level of risk.
◉ What are the characteristics of X-ray photons? Answer: X-ray
photons have a short wavelength and high energy, originating and
interacting at the atomic level.
◉ What are the genetic effects of ionising radiation? Answer:
Genetic effects occur in reproductive cells (egg and sperm) and may
affect future offspring.
,◉ What is the relationship between radiation dose and stochastic
effects? Answer: Increasing the radiation dose increases the chance
of stochastic damage occurring.
◉ What is the significance of the term 'ionising radiation'? Answer:
Ionising radiation has enough energy to remove tightly bound
electrons from atoms, which can lead to tissue damage.
◉ What is the potential risk associated with a single X-ray photon?
Answer: Although very unlikely, it has the potential to cause fatal
cancer.
◉ What is the role of physical methods in radiation protection?
Answer: Physical methods are used to reduce the level of risk
involved with radiation exposure.
◉ What is the nature of photons in the electromagnetic spectrum?
Answer: Photons come in a wide range of energies, with very low
energy making up radio waves and medium energy visible as light.
◉ What is the importance of understanding atomic interactions in X-
ray production? Answer: Understanding atomic interactions is
crucial for explaining how X-rays are produced.
, ◉ What are the basic features of dental X-ray generating equipment?
Answer: Dental X-ray equipment includes components like the
tubehead, X-ray tube, step-up transformer, oil for heat removal, and
a spacer cone for aiming the beam.
◉ What is the relevance of current recommendations and
regulations concerning X-ray equipment? Answer: Regulations
ensure safety and effectiveness in X-ray usage, including
specifications for equipment design, operation, and exposure limits.
◉ How do exposure variables kV, mA, and time affect dental X-ray
images? Answer: kV controls the energy and penetrating power of X-
ray photons; mA and time control the quantity of X-ray photons
produced, affecting film blackening.
◉ What is the effect of increasing kV on the contrast of a
radiographic image? Answer: Increasing kV decreases the contrast
between light and dark parts of the radiographic image, summarized
as 'kV kills contrast'.
◉ What happens to low-energy X-ray photons in the body? Answer:
Low-energy X-ray photons tend to be absorbed by soft tissues, which
can cause damage.
