Test examination

RPO MR-t

Tag one of the four alternatives (a, b, c or d) for each of the multiple-choice questions. Only one answer is correct. For the open questions 31 and 32, the complete calculations must be attached.

The examination is based on the syllabus Health physics for radiation protection officers - measurement and control applications - devices and accelerators, written by F. Pleiter, H.F. Boersma and A.A. Froma. You will find the correct answers here .

Complete the sentence correctly: The number of electrons in an electrically neutral atom is equal to the...
1. neutron number
2. atoomnummer
3. mass number
4. difference between mass number and atomic number
Complete the sentence correctly: Characteristic X-radiation arises...
1. if an electron returns from one shell to a lower-energy shell
2. if an electron is decelerated
3. if an electron is accelerated
4. during the process of Compton effect
Complete the sentence correctly: The probability of the photo-electric effect to occur...
1. hardly depends on the photon energy
2. hardly depends on the atomic number of the material
3. increases if the photon energy becomes higher
4. increases if the atomic number of the material becomes larger
During non-destructive material testing using a hand-held X-ray device, the technician wears personal protective clothing? Which one offers usually the best protection?
1. lead apron with a thickness of 0.25 lead-equivalent and a thyroid collar
2. lead apron with a thickness of 0.25 lead-equivalent without a thyroid collar
3. lead apron with a thickness of 0.35 lead-equivalent and a thyroid collar
4. lead apron with a thickness of 0.35 lead-equivalent without a thyroid collar
To answer the next question, you may use the transmission of X-radiation through plaster (see figuur A ).
The tube voltage of an X-ray device is 90 kV. How many mm plaster is needed to reduce the intensity of the X-ray beam by a factor of 50 ?
1. 100 mm
2. 120 mm
3. 150 mm
4. 190 mm
The tube voltage of the hand-held X-ray device for non-destructive material testing is 50 kV. During the investigation, the radiological technician wears a lead apron with a thickness of 0.25 mm, thus reducing the dose on the organs behind the lead apron by a factor equal to the transmission of the apron. To answer the next questions, you may use the transmission of X-radiation through lead (see figuur B ).
What is the transmission of the stone wall?
1. 0.0002
2. 0.006
3. 0.035
4. 0.1
Complete the sentence correctly: Protection against X-radiation usually relatively simple because...
1. the penetration depth of X-radiation into the body is very small
2. the radiation weighting factor wR for X-radiation is very small
3. the dose rate of an X-ray device is always very small
4. X-radiation usually can be shielded with a thin layer of lead
Complete the sentence correctly: If one decreases the voltage across the tube while not changing the other settings of the X-ray device, then...
1. the energy of the characteristic X-ray radiation decreases
2. the energy of the characteristic X-ray radiation remains the same
3. the energy of the characteristic X-ray radiation increases
4. the yield of the X-ray tube remains the same
The half-value thickness is the amount of material needed to reduce the dose rate by a factor of two.
Which property holds for the radiation that is generated by an X ray device?
1. the half-value thickness of the primary beam is larger than the half-value thickness of the scattered beam
2. the half-value thickness of the primary beam is smaller than the half-value thickness of the scattered beam
3. the half-value thickness increases when the exposure time increases
4. the half-value thickness decreases when the exposure time increases
Which combination of tube current and exposure time produces the largest output dose of an X-ray device, all other settings remaining the same?
1. 4 mA during 0.4 seconds
2. 5 mA during 0.3 seconds
3. 6 mA during 0.2 seconds
4. 7 mA during 0.1 seconds
In an organ with a mass of 100 grams, an energy of 2 joules is deposited by X-rays.
How high is the absorbed dose in that organ?
1. 0.02 Gy
2. 0.05 Gy
3. 20 Gy
4. 50 Gy
Complete the sentence correctly: The tissue weighting factor w_T is used for the conversion from...
1. only equivalent dose to effective dose
2. only absorbed dose to equivalent dose
3. neither equivalent dose to effective dose nor absorbed dose to equivalent dose
4. both equivalent dose to effective dose and absorbed dose to equivalent dose
During breast cancer screening among women, one of the two breasts receives an equivalent dose of 0.7 mSv. The tissue weighting factor for breast tissue is w_breast = 0.12.
What is the contribution of this exposure to the effective dose of the woman?
1. 0.042 mSv
2. 0.084 mSv
3. 0.7 mSv
4. 5.8 mSv
Almost half of the radiation dose due to natural sources in the Netherlands is caused by a single type of source.
Which type of radiation source is this?
1. soil
2. cosmic radiation
3. radon
4. food
What does the precise working of an ionization detector depend on?
1. the dimensions of the detector
2. the pressure of the counting gas
3. the composition of the counting gas
4. the voltage between anode en cathode
What is meant by "contrast of the photo" ?
1. the average brightness of the photo
2. the largest grey shade of the photo
3. the smallest grey shade of the photo
4. the difference in grey shades of light and dark parts of the photo
Complete the sentence correctly: A small grey shade means that...
1. the photo has a large average brightness
2. the photo has a small average brightness
3. the difference in brightness of light and dark parts of the photo is large
4. the difference in brightness of light and dark parts of the photo is small
In which type of tissue are cells most sensitive to ionizing radiation?
1. tissue that receives the largest dose
2. tissue that is located in the abdominal region
3. tissue with cells that no longer divide
4. tissue with cells that divide quickly
Which effect of ionizing radiation occurs with a probability that is not proportional to the received radiation dose?
1. a genetic effect
2. a stochastic effect
3. a tissue reaction
4. leukemia
Which disease can be regarded as a stochastic effect due to ionizing radiation?
1. leukemia
2. permanent sterility
3. temporary sterility
4. reduction in the number of white blood corpuscles
An unborn child receives an absorbed dose of 0.5 Gy during the first ten days after the conception.
What is the possible consequence of this irradiation for the child?
1. a tumor in later life
2. malformation of an organ
3. death shortly after birth
4. prenatal death
Which is the risk coefficient for fatal stochastic effects due to exposure to ionizing radiation?
1. about 0.01 per sievert
2. about 0.02 per sievert
3. about 0.05 per sievert
4. about 0.10 per sievert
What does the ALARA principle mean?
1. preference for any alternative method in which no ionizing radiation is applied
2. the received dose must be kept as low as reasonably achievable
3. the application must be justified, which means that the benefits outweigh the disadvantages
4. no dose limit shall be violated
According to the Decree on Basic Safety Standards Radiation Protection, which is the annual limit for the effective dose of an exposed category-A worker?
1. 100 μSv
2. 2 mSv
3. 20 mSv
4. 50 mSv
According to the Decree on Basic Safety Standards Radiation Protection, which is the annual limit for the equivalent dose on the lens of the eye of an exposed category-A worker?
1. 20 mSv
2. 50 mSv
3. 150 mSv
4. 500 mSv
Does a risk inventory and evaluation (RI&E) always have to be carried out by the radiation protection officer?
1. yes
2. no, this may only be done by a registered radiation protection expert
3. no, this may only be done by radiation protection experts
4. no, this may in principle be done by everyone
A special warning sign is described in the ANVS Ordonance Basic Safety Standards Radiation Protection (see figure ).
On which device must this warning sign be attached?
1. a baggage scanner
2. a transmission electron microscope
3. neither a baggage scanner nor a transmission electron microscope
4. both a baggage scanner and a transmission electron microscope
Complete the sentence correctly: A CT-scanner...
1. may be used without any restrictions
2. is subject to a license
3. may be used without a radiation protection officer
4. must be registered with the ANVS
Consider the following two instructions to new employees:
Instruction I: Introducton into the house rules.
Instruction II: Introduction into the written protocols.
Which instruction belongs and which does not belong to the duties of the radiation protection officer?
1. instruction I and instruction II are both duties
2. neither instruction I nor instruction II are duties
3. instruction I is not to a duty, but instruction II is
4. instruction I is a duty, but instruction II is not
The voltage across the X-ray tube is set to 70 kV. The maintenance engineer replaces the existing filter of 2 mm aluminum with a 3 mm aluminum filter. The equivalent entrance dose with the old filter was 1 mSv. To answer the next question, you may use the data in figure C

What is the equivalent entrance dose with the new filter?

about 0.3 mSv
about 0.7 mSv
about 1.1 mSv
about 1.5 mSv

To answer questions 31 and 32, the full calculation must be given. Clearly indicate the calculation method and/or reasoning you use to arrive at the solution. Always state the quantities and units used.

Data for question 31
tube voltage	110 kV
filter	3 mm aluminum
yield of X-ray tube	see figure C
tube current	6 mA
exposure time	0.3 seconds
distance focus - skin	50 cm

During maintenance on the X-ray device, the service engineer inadvertently keeps his hand in the direct beam.

Calculate the equivalent skin dose.
(maximaal 4 punten)

Data for question 32
tube voltage	50 kV
filter	2 mm aluminum
yield of X-ray tube	see figure C
tube current	0.005 mA
exposure time	25 seconds
distance focus - skin	5 cm
number of inspections	30 per day
number of work days	200 per year

The final inspection of an alloy is carried out using a hand-held X-ray device. The worker has the habit of holding the product in his hand during those checks so that large areas of the skin are exposed to the direct beam each time.

1. Calculate the equivalent dose on the skin per inspection.
2. Calculate the equivalent dose on the skin per year.
(maximal 6 points)

Last modified:23 December 2025 4.13 p.m.

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Test examination

To answer questions 31 and 32, the full calculation must be given. Clearly indicate the calculation method and/or reasoning you use to arrive at the solution. Always state the quantities and units used.

Data for question 31

Data for question 32