BDA RADIOGRAPHY AND RADIOLOGY ACTUAL
EXAM PAPER 2026 QUESTIONS WITH
ANSWERS 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.
◉ What is the advantage of high-energy X-ray photons? Answer: High-
energy X-ray photons pass through soft tissues and hit the film, making
them more diagnostically useful.
EXAM PAPER 2026 QUESTIONS WITH
ANSWERS 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.
◉ What is the advantage of high-energy X-ray photons? Answer: High-
energy X-ray photons pass through soft tissues and hit the film, making
them more diagnostically useful.
