BDA RADIOGRAPHY AND RADIOLOGY STUDY
GUIDE 2026 QUESTIONS WITH ANSWERS
GRADED A+
◉ What's indirect action film. Answer: Extra oral with intensifying
screen & cassette . sensitive to light photons
◉ Why is direct action film used for intra oral. Answer: For excellent
image quality
◉ black paper is used on either side of the film to protect the film
from..? Answer: Light
damage by fingers
saliva that may leak into film packet
◉ Why is a thin sheet of lead foil placed behind the film? Answer: To
stop residual radiation going further into pt tissues
To stop secondary radiation from scattering back onto film and
degrading the image
If film was placed wrong way in pts mouth the lead foil would show on
radiograph making the fault easily identified
◉ Increasing the Ma will make the image. Answer: too dark/blacken
, ◉ Decreasing the mA will make the image. Answer: Too white / light
◉ What % of energy is conducted as heat and X-rays ? Answer: Heat -
99%
Xrays - 1%
◉ What is the recommended FSD. Answer: 200mm or 20cm
◉ What are the dose units used for radiography. Answer: Radiation
absorbed dose
Equivalent dose
Effective dose
◉ What dose is the actual dose patients are interested in? Answer:
Effective dose
◉ What is the effective dose from one intra oral radiograph ? Answer:
0.022&0.0003 millisievert msv
◉ What are the steps involved for effective dose ? Answer: Radiation
absorbed dose x weighting factor = equivalent dose
Equivalent dose x tissue weighting factor = effective dose
GUIDE 2026 QUESTIONS WITH ANSWERS
GRADED A+
◉ What's indirect action film. Answer: Extra oral with intensifying
screen & cassette . sensitive to light photons
◉ Why is direct action film used for intra oral. Answer: For excellent
image quality
◉ black paper is used on either side of the film to protect the film
from..? Answer: Light
damage by fingers
saliva that may leak into film packet
◉ Why is a thin sheet of lead foil placed behind the film? Answer: To
stop residual radiation going further into pt tissues
To stop secondary radiation from scattering back onto film and
degrading the image
If film was placed wrong way in pts mouth the lead foil would show on
radiograph making the fault easily identified
◉ Increasing the Ma will make the image. Answer: too dark/blacken
, ◉ Decreasing the mA will make the image. Answer: Too white / light
◉ What % of energy is conducted as heat and X-rays ? Answer: Heat -
99%
Xrays - 1%
◉ What is the recommended FSD. Answer: 200mm or 20cm
◉ What are the dose units used for radiography. Answer: Radiation
absorbed dose
Equivalent dose
Effective dose
◉ What dose is the actual dose patients are interested in? Answer:
Effective dose
◉ What is the effective dose from one intra oral radiograph ? Answer:
0.022&0.0003 millisievert msv
◉ What are the steps involved for effective dose ? Answer: Radiation
absorbed dose x weighting factor = equivalent dose
Equivalent dose x tissue weighting factor = effective dose
