CERTIFICATION EVALUATION EXAMS 2026
SOLVED QUESTIONS AND SOLUTIONS
GRADED A+
⩥ Which component of the x-ray tube serves as the source of free
electrons? Answer: Cathode filament (The filament releases electrons
when heated by a large current through a process called thermionic
emission).
⩥ What technical factor is responsible for accelerating electrons through
the x-ray tube? Answer: kVp-This voltage causes the cathode to become
negatively charged and the anode becomes positively charged. Electrons
are repelled from the negative charge of the cathode and attracted to the
positive charge of the anode.
⩥ Which aspect of the x-ray tube assembly is the actual source of x-ray
photons? Answer: Anode Target-The emission of x-rays occurs when
electrons created at the cathode have been accelerated through the tube
by the kVp and collide with the anode.
⩥ Thermionic emission is the process within the x-ray tube directly
responsible for creating: Answer: Free Electrons-Thermionic emission is
the process that creates free electrons. This phenomenon occurs when
the filament is heated by a large current.
,⩥ Which component of the x-ray tube becomes negatively charged
during an x-ray exposure? Answer: The cathode filament- This is
essential to ensure that electrons are repelled from the negative charge of
the cathode and attracted to the positive charge of the anode.
⩥ What technical factor is primarily responsible for controlling the
energy of the x-ray beam? Answer: kVp- For example, increasing the
kVp results in an increase in the energy of electrons colliding with the
anode and an increase in the resulting x-ray created. kVp also has a
significant influence on beam energy.
⩥ What condition is required to induce thermionic emission within the
cathode filament? Answer: High Current- Thermionic emission is
induced in the filament when a high current is applied. A high current
produces significant heat which in turn creates free electrons.
⩥ Exposure of obese patients results in inadequate receptor exposure.
What technical factor should be modified to increase the energy and
penetrability of the x-ray beam? Answer: kVp- Increasing kVp is used
when imaging obese patients to ensure an adequate number of photons
penetrate through the patient and reach the image receptor. The tube
current (mA) and exposure time change the total number of x-rays in the
beam, but not the energy of photons.
⩥ The charge difference between the cathode and anode within the x-ray
tube is controlled by the: Answer: kVp-The anode and cathode are
,electrically neutral until the tube voltage (kVp) is applied, at which point
the cathode becomes negatively charged and the anode becomes
positively charged.
⩥ A portable chest x-ray demonstrates excessive exposure. How can the
technologist decrease the intensity of the x-ray beam while maintaining
the same beam energy? Answer: Decrease mA- Beam intensity or the
number of x-ray photons can be decreased by decreasing the mA.
Decreasing the kVp would have the same effect, but the beam energy
would also be decreased.
⩥ Which of the following statements correctly describe the flow of
electrons through an x-ray tube? Answer: Cathode to Anode-This occurs
because electrons are repelled from the negative charge of the cathode
and attracted to the positive charge of the anode.
⩥ During an attempted x-ray exposure, the x-ray tube fails to create any
x-ray photons. Which of the following conditions is most likely to
explain this failure? Answer: Breakage of the cathode filament- When
the filament is broken, no current can flow through the filament, no heat
can be created, no free electrons can form, and in the absence of free
electrons, no x-rays can be created at the anode.
⩥ What is the primary product of electron collisions at the anode of the
x-ray tube? Answer: Heat 99%, X-rays make up 1%
, ⩥ The term for electron production Answer: thermionic emission
⩥ Bremsstrahlung radiation is created within the x-ray tube when high-
energy electrons interact with: Answer: Electric field of the nucleus-The
negatively charged electrons are attracted to the positive charge of the
nucleus. This causes the incident electrons to change directions, slow
down, and release a bremsstrahlung photon.
⩥ Bremsstrahlung is a German term defined as: Answer: Braking
radiation-Incident electrons slow down, or brake, as they pass through
the positive electric field of the tungsten nucleus. The energy lost
through slowing down is released as a bremsstrahlung photon.
⩥ The energy of a bremsstrahlung photon is dependent on which of the
following variables?
1. Energy of the incident electron
2. Binding energy of orbital electrons
3. Proximity of the incident electron to the nucleus Answer: 1. Energy of
the incident electron
3. Proximity of the electron to the nucleus.
If the incident electron carries a large amount of energy, this electron can
potentially release a high energy photon. The proximity of the electron
to the nucleus affects bremsstrahlung photon energy in that electrons
passing closer to the nucleus will be more highly attracted to the
nucleus, slow down more, and release a higher energy bremsstrahlung
photon. The binding energy of orbital electrons does not affect