RHS EXAMINATION 2025

What is the maximum permisible dose (MPD) of radiation.for am ocupattionally exposed worker per year?

50 Msv (5 rem) per year.

The unit used to measure radiation absorbed by tissue is:

A. Roentgen

B. REM

C. Gray (Gy)

D. Sievert (Sv)

C. Gray

Which unit measures radiation exposure in the air?

A. Gray

B. Sievert

C. Roentgen

D. REM

C. Roentgen

The Numbers of electron is controlled by

Milliamperage

Which of the following helps reduce patient exposure radiation?

•Fast film

• longer PID (16 inch)

• Lead apron and thyroid collar

• all of above

All of above

As the density and of matter increases what characteristic of an x ray must be increased in order to penetrate it?

Wavelength

What is the function of the collimator in a x-ray machine?

It restricts the size and shape of the x ray beam to reduce scatter radiation.

What is the correct vertical angulation for a bitewing radiograph?

10 +

If the x ray beam is directed too sleepy (excessive vertical angulation) what error will likely occur?

Foreshortening

In the bisecting angle technique which of the following is the ideal vertical angulation for a mandibular molar radiograph?

-30 degrees

What is the porpuse of using the correct horizontal angulation in radiography?

To avoid overlap of teeth in the radiograph.

What happen if the x ray tube is angled incorrectly during the exposure, and the image becomes distorted?

Distortion

Which of the following describes the correct horizontal angulation for a bitewing radiograph?

The x ray beam should be directed at a right angle (90 degrees) to film

Which of the following will result in an image with excessive distortion when using the bisecting angle technique?

Incorrect vertical angulation

What is the proper horizontal angulation for a periapical radiograph of the maxillary first molar?

0 degrees

In a panoramic radiograph, what is the recommended angulation of the x ray beam in relation to the patient occlusal plane?

The x ray should be angled slightly downward

What would likely occur if the angulation is too flat (insufficient vertical angulation) in a periapical radiograph?

The image will be elongated .

Cone cutting occurs when:

The x ray beam does not fully cover the film or sensor.

Which landmark appears as a Radiolucent area between the maxillary central incisor?

Incisive foramen

Which structure appears as a U shaped radiopacity superior to the maxillary first molar?

Zygomatic process

Which anatomical structure appears as a radiopaque inverted Y near the maxillary canine region?

Nasal cavity and maxillary sinus intersection

The mental foramen is most commonly found near the?

Mandibular premolars

After taking radiographs, the lead apron should be?

Disinfected with a surface cleaner.

A patient with a strong gag flex has difficulty with Intraoral radiographs. What is the best solution?

Use distraction techniques and deep breathing

X ray are form of:

Electromagnetic radiation

The quality (penetrating power) of an x ray beam is controlled by :

Kilovoltage (kvp)

If the kilovoltage is increased , the image will appear:

Darker

What is the primary purpose of the lead apron and thyroid collar ?

To protect the patient from scatter radiation

The Alara principle stands for:

As low reasonably achiavle

What is the most affective way to reduce radiation exposure to the patient?

Using digital sensors of fast film

A radiograph appear too light what is the most likely cause?

Underexposure

A herringbone (tine track) pattern on a film indicates?

The film was placed backward in the holder

If a panoramic image is blurry with overlapping teeth in the anterior region, the most likely cause is:

The patient was too far forward on the biteblock

After exposing radiograph contamined film packets should be :

Opened with gloves and handled using clean hands

How should lead aprons be shorted?

Hung on support rod or draped over a chair.

Which of the following is true about processing solutions in an automatic processor ?

Developer and fixer levels should be checked daily

The process by which electrons are removed from atoms, creating ion pairs, is called:

Ionization

The penetrating power of an x ray is controlled by?

Kilovoltage

If the target - film distance is increased, the image will appear :

Lighter

The most effective way to reduce radiation exposure exposure to the operator is :

Standing at least 6 feet away and at a 90-135 angle from the primary beam

The mandibular canal appears as :

A Radiolucent band outline by thin radiopaque lines

A dosimeter badge measure

The amount of radiation exposure over time

The MPD maximum permissible dose for a pregnant dental worker is :

0.5 msv per month

The main porpuse of the intensifying screen in extraoral radiographs is to :

Decrease exposure time

A radiograph that appear brownish after a few months is likely due to:

Incomplete washing during processing

A panoramic image with a flattened widened smile and exaggerate anterior teeth is due to?

The patients chin being too high

A double exposure occurs when ?

The same films is exposed twice .

What causes a radiograph to have elongation?

Too little vertical angulation

A light leak in the darkroom will cause the film to appear:

Black

The mental foramen is often mistaken for :

Periapical access

Which landmark appears as a a radiopaque hook line projection behind the maxillary tuberosity ?

Hamular process

The function of the aluminum filter in an x ray tube head is=

Remove low energy , long wavelength x rays

Increasing the milliamperage (MA) will result in:

A darker image

What is the minimum required thickness of a lead apron used for radiation protection

0.5 mm

When taking dental radiographs, the greatest risk of radiation exposure to the patient comes from:

Repeated exposures due to errors.

The safest place for the operator to stand during and x ray exposure is

Behind a lead barrier or wall

What is the primary cause of film fogging

Light exposure before processing

A radiograph that appears too dark may be caused by:

Excessive exposure time

If a radiograph appears too light, the cause may be:

Under developing or insufficient exposure time.

A patient x ray show a cone cut, what is the cause?

The PID was not centered over the film or sensor.

What is the likely cause of herringbone or time track pattern on a film ?

The film was placed backward in the mouth

Which of the following appears radiopaque on a radiograph ?

Enamel

What is the radiograph appearance of the mandibular canal?

Radiolucent band outlined by thing radiopaque borders

Which landmark appears as a Radiolucent are between the maxillary central incisor ?

Incisive foramen

How should lead aprons be stored?

Hung on a support rod or draped over a chair .

When using a daylight loader for film processing, the operator should?

Open film packets with clean hands

A panoramic radiograph shows an exaggerated “smile appearance, what is the error ?

Patients chin was too low

In the bisecting technique, the central ray should be directed?

Perpendicular to bisector line

What is the result of using excessive vertical angulation during periapical radiography?

Foreshortening of tooth image .

If a patient chin is positioned too low during a panoramic radiograph how will the image appear

Exaggerated smile appearance

Which of the following is considered a critical instrument In dental radiography?

Film holding device

A radiograph exhibits a clear (white) areas on one edge. What is the most likely cause?

Cone- cutting due to misaligned PID.

Which radiographic technique is recommended for a exposing periapical images to minimize distortion?

Paralleling technique

Which unit is used to measure the absorbed dose of radiation ?

RAD

How should a dental assistant manage a patient with a strong gag reflex ?

Apply a topical anesthetic to the soft palate

What is the recommended method for sterilizing lead- sensitive instruments?

Ethylene oxide gas sterilization

Which dental material is commonly used for permanent restoration due to its durability and esthetic quality?

Composite resin

In the universal numbering system which tooth is designated as tooth number 12?

Maxillary left first molar

In the universal numbering system which tooth number 8?

Maxillary right central incisor .

Which radiograph technique minimizes distortion and provides the most accurate image of the tooth structure?

Paralleling technique

Which tooth is designed as tooth number 19 in the universal numbering system?

Mandibular left first molar

In dental charting, what does a red colored notation typically indicate?

Treatment planned

Which of the following best describes low level disinfection?

Kills vegetative bacteria and some viruses but not bacteria spores

Iodophors are classified under which level of disinfected?

Intermediate to low

Which low level disinfected as known to be incompatible with soap?

Quaternary ammonium compounds

How long must Alcohol remain in wet contact with an item to achieve a reasonable level of desinfection ?

10 minutes

According to CCD guidelines how many levels of desinfection are recognized for patient care ítems that do not require stiriliy ?

Three

Step wedge

Automatic processor

Wich of the following is considered to be the yearly permissible dose (MPD) for dental patient ?

10 msv / 0.1 rem

The maximum whole body dose considered permisible dose who work with radiation is

0.1 rem/ week

Biohazard

Infectious waste

Exclamation

Acute toxicity

Regulatory (federal)

What does OSHA stand for?

Occupational safety and health administration

What does CDC stand for?

Center for Disease control and prevention

Is CDC regulatory or advisory?

Advisory (federal)

Is OSHA regulatory or advisory ?

Regulatory (federal)

The EPA ensures the safety of all of the following except ?

Labeling of medical devices