CBET Cheat Sheet 2026

The 30 highest-yield CBET facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What principle does an ultrasound imaging system use to create images of internal body structures? → Piezoelectric transducer emitting and receiving high-frequency sound waves
2. A hospital wants to segment its biomedical device network from the administrative network. Which technology accomplishes this at Layer 2? → VLAN (Virtual LAN)
3. When performing preventive maintenance on an infusion pump, which test verifies the accuracy of fluid delivery rate? → Gravimetric flow rate test
4. Which of the following best describes the function of an optocoupler (optoisolator) in medical equipment? → Transmitting signals between circuits while maintaining electrical isolation
5. What is the primary physiological purpose of Positive End-Expiratory Pressure (PEEP) in a mechanically ventilated patient? → To prevent alveolar collapse (atelectasis) at end-expiration and improve oxygenation
6. During inspiration, the diaphragm contracts and moves inferiorly, causing intrathoracic pressure to: → Decrease, drawing air into the lungs
7. What is the primary hazard associated with improper grounding of a surgical robot in the OR? → Leakage current could flow through the patient, causing burns or cardiac events
8. Which type of medical gas outlet connector system uses non-interchangeable, gas-specific body configurations to prevent misconnections? → Both DISS and NIST
9. When calibrating a patient scale used for medication dosing, a biomedical technician should use NIST-traceable weights primarily to: → Ensure measurements are accurate relative to a national standard
10. What forces drive the kidneys' filtration? → Blood pressure
11. In a bulk liquid oxygen system, what safety device prevents overpressure in the storage vessel? → Pressure relief valve
12. What minimum purity level is required for medical-grade oxygen supplied by bulk cryogenic systems in the US? → 99%
13. During ultrasound transducer acceptance testing, a BMET uses a tissue-equivalent phantom to assess: → Dead elements, sensitivity uniformity, and depth penetration
14. What is the purpose of the smoke evacuator in a surgical laser procedure? → Remove laser plume containing viable cellular material and toxic byproducts
15. Which standard governs the safe use of electrical equipment in patient care areas in US hospitals? → NFPA 99
16. Which safety feature prevents inadvertent activation of an electrosurgical unit when the active electrode is not in use? → Holster with passive safety switch
17. The primary purpose of a Faraday cage in a medical imaging suite is to: → Prevent external RF signals from interfering with MRI signals
18. An infusion pump displays a 'door open' alarm even though the door is fully closed and latched. What troubleshooting approach should you take first? → Inspect the door latch mechanism and door switch for mechanical wear or debris
19. Which standard organization publishes guidelines for medical device electrical safety in the US? → AAMI
20. A hospital bed's weight scale consistently reads 5 kg below the known weight of a calibration mass. Which corrective action is most appropriate? → Perform a span calibration adjustment using NIST-traceable weights
21. Which type of current flows in only one direction through a circuit? → Direct current (DC)
22. Which mathematical relationship describes exponential decay in an RC circuit? → V(t) = V₀ × e^(-t/RC)
23. A flash sterilization cycle (immediate-use steam sterilization) at 132°C in a pre-vacuum sterilizer requires a minimum exposure time of: → 4 minutes
24. Which standard specifies that the maximum allowable leakage current for chassis-to-ground on patient care equipment (normal condition) is 300 µA? → ANSI/AAMI ES60601-1
25. In a full-wave bridge rectifier with four diodes, the output ripple frequency relative to the AC input frequency is: → Double (2×)
26. In a pulse oximeter, which physiological principle is used to differentiate oxygenated from deoxygenated hemoglobin? → Differential light absorption at two wavelengths (660 nm and 940 nm)
27. During preventive maintenance on a ventilator, the BIOMED finds the exhalation valve is slow to close. The MOST immediate patient safety concern is: → Inadequate tidal volume delivery due to gas leakage
28. How should a biomedical technician verify that a repaired medical gas outlet is delivering the correct gas before returning it to service? → Use a gas-specific analyzer to verify gas identity, then test flow rate and pressure
29. A washer-disinfector used for surgical instrument reprocessing must achieve what temperature during the thermal disinfection phase to meet A0 600 standard? → 90°C for 1 minute
30. A pulse oximeter reads 98% SpO2 but the patient appears cyanotic. Which condition MOST likely explains this discrepancy? → Carbon monoxide poisoning causing carboxyhemoglobin