FR FieldReady Academy
Certified Associate in Biomedical Technology CABT

Certified Associate in Biomedical Technology CABT Practice Test: 20 Free Questions with Answers

Twenty questions in the exam's domain weights, each with its answer and the reason. The full course has 293 explained questions plus generated math items, scored tests in the real exam's format, and lessons built from what you miss.

  1. A nurse asks you to relocate a pulse oximeter probe from a patient's earlobe to a more distal site. In which direction are you moving?

    1. Farther away from the trunk, such as a fingertip
    2. Closer to the trunk, such as the shoulder or the upper arm
    3. Toward the midline of the body
    4. Toward the back of the body
    Show the answer

    Answer: A. Proximal means nearer the trunk and distal means farther from it. The reference is always the trunk, so a more distal site on a limb is farther out, toward the fingers or toes.

    From the lesson Body Organization, Directions, and Word Parts.

  2. A bedside monitor is displaying a heart rate of 88. Which part of the tracing is it counting to produce that number?

    1. The P wave
    2. The QRS complex
    3. The T wave
    4. The flat stretch after the P wave
    Show the answer

    Answer: B. The QRS complex is the tall spike of ventricular depolarization, and monitors count those to report a rate. The P wave is the atria and the T wave is the ventricles recovering.

    From the lesson The Heart, Circulation, and the Numbers a Monitor Shows.

  3. A clinic sends you an otoscope because 'the light is too dim to see anything.' What does the device do, and where do you look first?

    1. It measures ear temperature by infrared, so check the sensor window, the probe cover supply, and the ambient compensation setting
    2. It lights and magnifies the ear canal, so check the lamp, the battery or charger contacts, and the specula
    3. It lights the back of the eye through the pupil, so check the lens dial, the diopter wheel, and the aperture selector for a stuck setting
    4. It measures pressure in the ear, so check for leaks
    Show the answer

    Answer: B. An otoscope lights and magnifies the ear canal and eardrum through a disposable or cleanable specula on a battery or rechargeable handle. A dim lamp is almost always the lamp itself, the battery, or dirty charger contacts, not the optics.

    From the lesson Diagnostic Devices.

  4. A monitor on a telemetry floor keeps raising an asystole alarm on a patient who is sitting up and talking. What does the monitor count, and what is the likely cause?

    1. It counts breaths by chest impedance, so a disconnected respiration cable or a loose belt sensor is the likely cause
    2. It counts cuff cycles, so the NIBP hose is leaking
    3. It counts the QRS complex, so a dried-out electrode or a broken lead wire is the likely cause
    4. It counts the pulses of light returning from the finger, so a cracked oximeter probe or a dim emitter is the likely cause
    Show the answer

    Answer: C. A monitor derives heart rate by counting QRS complexes from the ECG signal, so anything that spoils that signal mimics a flat line. Dried-out electrode gel and lead wires broken from flexing at the ends are the two usual causes.

    From the lesson Patient Monitoring.

  5. You connect a patient simulator to a monitor and every number matches its tolerance. A colleague says the monitor is now cleared for patient use. What is missing?

    1. Nothing; a simulator check covers performance and safety, because its signals pass through the same patient leads the analyzer would test
    2. A software update from the manufacturer, because the simulator check is only valid on the current validated release of the monitor firmware
    3. A second simulator at a different rate
    4. The electrical safety test, because a simulator draws no current and proves nothing about ground or leakage
    Show the answer

    Answer: D. A patient simulator supplies known signals and draws essentially no current, so it verifies performance only. Ground resistance and leakage currents are measured by an electrical safety analyzer, and that test comes before the performance work.

    From the lesson Verifying a Monitor With a Patient Simulator.

  6. A nurse programs a large-volume pump with a rate of 125 and a VTBI of 500. What has she told the pump?

    1. Deliver 125 mL/h until a total of 500 mL has been infused, then stop or drop to a keep vein open trickle
    2. Deliver 125 mL in total, spread across 500 minutes, then alarm and stop when either the volume or the time is reached
    3. Deliver 125 drops per minute for 500 minutes
    4. Deliver 500 mL/h for 125 minutes
    Show the answer

    Answer: A. Rate is programmed in mL/h and says how fast; volume to be infused is the total to deliver before the pump stops and alarms. After that total, the pump either stops or drops to the keep vein open rate so the line does not clot.

    From the lesson Infusion Devices.

  7. A patient has a fluid-filled catheter running to the heart. How little current, delivered through that path, can cause fibrillation?

    1. About 10 microamps
    2. About 1 mA
    3. About 10 mA
    4. About 100 mA
    Show the answer

    Answer: A. That is microshock: as little as 10 microamps delivered directly to the heart can cause fibrillation, because the skin is not in the path and nothing spreads the current out. It is a current nobody can feel, from a device that looks healthy.

    From the lesson Electrical Safety: Macroshock, Microshock, and Why Leakage Matters.

  8. The analyzer reports a ground wire resistance of 0.62 ohm from the chassis to the plug's ground pin. What is the verdict and the likely cause?

    1. Pass: under one ohm is acceptable
    2. Fail: the limit is 0.5 ohm, and the cord, plug, or strain relief is the usual cause
    3. Fail: the limit is 0.1 ohm, so the main board's ground connection is at fault and must be resoldered
    4. Pass, but only if chassis leakage also passes
    Show the answer

    Answer: B. NFPA 99 sets ground wire resistance for patient-care equipment at 0.5 ohm maximum, so 0.62 ohm fails. A high ground reading is almost always the cord, the plug, a damaged strain relief, or a corroded ground screw, not the electronics.

    From the lesson The Electrical Safety Test: Ground Resistance and Leakage.

  9. A pressure monitoring device connects to the patient through a catheter that reaches the heart. What is its patient leakage limit in the normal condition, and under which standard?

    1. 500 microamps, under NFPA 99
    2. 100 microamps, under IEC 60601-1
    3. 10 microamps, under IEC 60601-1
    4. 5 mA, under IEC 60601-1
    Show the answer

    Answer: C. A direct cardiac connection means a type CF applied part, and IEC 60601-1 allows only 10 microamps of patient leakage in the normal condition and 50 microamps in a single fault condition, ten times tighter than type B and BF.

    From the lesson Reading the Limits: NFPA 99, IEC 60601-1, and a Failing Device.

  10. A test report lists a measured leakage of 0.0005 A. Your paperwork wants the value in microamps. What do you write?

    1. 50 microamps
    2. 5 microamps
    3. 500 microamps
    4. 5,000 microamps
    Show the answer

    Answer: C. One amp is 1,000,000 microamps, so multiply by a million: 0.0005 x 1,000,000 = 500 microamps. Moving three decimal places per prefix step is the whole trick, and 0.0005 A is also 0.5 mA.

    From the lesson Charge, Current, Voltage, and Resistance.

  11. A heater element measures 6 ohm and sits across a 24 V supply. How much current does it draw?

    1. 18 A
    2. 0.25 A
    3. 144 A
    4. 4 A
    Show the answer

    Answer: D. I = V / R = 24 / 6 = 4 A. Cover the I in the triangle and you are left with V over R. Keep the units plain: volts divided by ohms gives amps.

    From the lesson Ohm's Law and Power.

  12. A 100 ohm and a 200 ohm resistor sit in series across a 9 V battery. What voltage appears across the 200 ohm part?

    1. 6 V
    2. 3 V
    3. 9 V
    4. 4.5 V
    Show the answer

    Answer: A. Total resistance is 300 ohm, so the current is 9 / 300 = 0.03 A. Across 200 ohm that is 0.03 x 200 = 6 V, and the 100 ohm part takes the remaining 3 V. The two drops always add up to the source.

    From the lesson Series and Parallel Circuits.

  13. Your analyzer displays a chassis leakage of 0.35 mA and the limits card on the bench is written in microamps. What do you write in the record?

    1. 35 microamps
    2. 350 microamps
    3. 3,500 microamps
    4. 0.00035 microamps
    Show the answer

    Answer: B. Milli to micro is three decimal places to the right, so 0.35 x 1,000 = 350 microamps. Smaller unit, bigger number. Against a 500 microamp limit that reading passes, but only once it is converted.

    From the lesson Metric Prefixes and Unit Conversions.

  14. The analog voltmeter you are using is on its 0 to 50 V range, five divisions sit between 20 and 25, and the needle rests two divisions past the 20 mark. What is the reading?

    1. 20.2 V
    2. 24 V
    3. 22 V
    4. 27 V
    Show the answer

    Answer: C. Five divisions between 20 and 25 makes each division 5 / 5 = 1 V. Two divisions past 20 is 22 V. Always work out the value of one division before reading the needle, and read square-on so parallax does not add a division.

    From the lesson Reading Scales, Meters, and Cylinders; Tolerance and Percent Error.

  15. On a strip recorded at 25 mm/s you count five large boxes between two R waves. What is the heart rate?

    1. 50 beats per minute
    2. 100 beats per minute
    3. 75 beats per minute
    4. 60 beats per minute
    Show the answer

    Answer: D. The 300 method: 300 divided by the number of large boxes between R waves, so 300 / 5 = 60 beats per minute. A large box is 5 mm, which is 0.2 s at 25 mm/s, so five of them is one second per beat.

    From the lesson Reading Waveforms: ECG Paper, Period, Amplitude, and Rate.

  16. The last three scheduled inspections of a monitor recorded chassis leakage of 90, then 150, then 310 microamps, against a 500 microamp limit. What should you do?

    1. Flag it for investigation now, because the trend predicts a failure
    2. Nothing: all three readings pass
    3. Fail it now, because the reading tripled
    4. Average the three readings and record 183 microamps as this year's value
    Show the answer

    Answer: A. Every reading passes and the device is still failing: leakage that roughly doubles each year will cross the limit before the next visit. Compare each reading with the last one, not only with the limit, and act while it is planned work.

    From the lesson Graphs, Tables, and Trend Data.

  17. Following a manufacturer's troubleshooting chart, you reach a diamond-shaped box. What does that shape tell you to do?

    1. Perform a step such as a measurement or an adjustment, then move on
    2. Answer a yes or no question with a test you have run
    3. Stop: this is the end of the chart
    4. Start over from the beginning
    Show the answer

    Answer: B. Oval is start or end, rectangle is a step, diamond is a decision answered yes or no, and the arrows show which branch each answer takes. Answer a diamond with a test you actually performed, not with the answer you expect.

    From the lesson Flowcharts and the Process of Elimination.

  18. A workstation on a nursing unit loses everything a clinician had typed whenever the power blips, though its saved files survive. Which part explains that?

    1. The motherboard, because it carries the buses
    2. The hard drive, because the platters stop spinning before the heads finish writing the file to the disk
    3. The GPU, because the display is redrawn
    4. RAM, because working memory is volatile and its contents disappear when power drops
    Show the answer

    Answer: D. Working memory is volatile: everything in it is gone the instant power is removed. Storage, whether a hard drive or a solid-state drive, keeps its contents with the power off, which is why saved files survive and unsaved work does not.

    From the lesson Inside a Computer.

  19. You find an unlabeled cable with a nine-pin two-row connector in a metal shell with thumbscrews. What is it, and what is it used for on medical devices?

    1. An RS-232 serial connector on a DB9 shell, used for service menus, logs, and data output
    2. A VGA video connector, used for external displays and strip printers that take an analog picture signal
    3. An RJ45 network connector, used for the device segment
    4. A DVI connector, used for imaging displays
    Show the answer

    Answer: A. Nine pins in two rows inside a shell with thumbscrews is a DB9, and on medical equipment it almost always carries RS-232 serial. It is how you reach a service menu, pull a log, or feed a strip printer, and a serial-to-USB adapter needs a driver.

    From the lesson Connectors and Cables.

  20. A central station at 10.20.4.57 with a mask of 255.255.255.0 cannot reach a server at 10.20.9.20. Are the two on the same subnet?

    1. Yes, because both addresses begin with 10.20, and a 255.255.255.0 mask only separates hosts whose first two numbers differ
    2. No, because with that mask only 10.20.4.x is local, so traffic to the server goes through the gateway
    3. Yes, because they are in the same building
    4. It cannot be determined from the addresses
    Show the answer

    Answer: B. A mask of 255.255.255.0 makes the first three numbers the network. 10.20.4 and 10.20.9 differ, so the server is on another subnet, probably another VLAN, and every packet to it crosses the default gateway.

    From the lesson Networks: LAN, WAN, Wi-Fi, and the Data Closet.