CBET Practice Questions (2026) — Free Sample Questions with Answers

Answer: B

P wave: The P wave represents atrial depolarization, triggered by the SA node.

QRS complex: Correct. The QRS complex reflects depolarization of the ventricles through the bundle branches and Purkinje fibers.

T wave: The T wave represents ventricular repolarization.

PR interval: The PR interval reflects conduction from the atria through the AV node to the ventricles, not ventricular depolarization itself.

ECG basics: P = atrial depolarization, QRS = ventricular depolarization (atrial repolarization is hidden in it), T = ventricular repolarization; the SA node is the normal pacemaker.

Answer: C

The magnet is off between scans, so any tool may be used: Superconducting MRI magnets stay at full field strength at all times, even when no images are being acquired.

Only ferrous tools are safe because they ground static: Ferrous (iron-containing) tools are the main projectile hazard in the magnet room.

The field is always on; bring only MR-safe items in: Correct. Screen yourself and bring only MR Safe or appropriate MR Conditional equipment and tools into Zone IV, coordinating with MRI staff.

Wearing a lead apron gives protection from the field: Lead aprons protect against ionizing radiation, which MRI does not use; they offer no protection from the magnetic field.

MRI magnets are always on: ferromagnetic objects become projectiles, so screen people and items and allow only MR Safe/MR Conditional equipment in Zone IV.

Answer: C

0.25 W: 0.25 is the current in amperes (12 V / 48 Ω), not the power.

4 W: 4 results from dividing resistance by voltage (48 / 12), which is not a valid power formula.

3 W: Correct. P = V² / R = 144 / 48 = 3 W (equivalently I = 0.25 A and P = V × I = 12 × 0.25 = 3 W).

576 W: 576 is V × R (12 × 48), which has no physical meaning as power.

Ohm's law V = IR; power P = VI = I²R = V²/R. Check that the resistor's wattage rating exceeds the calculated dissipation.

Answer: A

Red/infrared absorbance ratio in pulsatile blood: Correct. Oxyhemoglobin and deoxyhemoglobin absorb red (about 660 nm) and infrared (about 940 nm) light differently; the ratio of pulsatile absorbances is converted to SpO2 by a calibration curve.

Electrochemical measurement of dissolved oxygen in the skin: Electrochemical (Clark) electrodes measure PO2 in blood-gas or transcutaneous monitors, not SpO2.

Thermal conductivity difference between oxygen and nitrogen: Thermal conductivity is used in some gas analyzers, not in pulse oximetry.

Ultrasound Doppler shift from red cells in the fingertip: Doppler measures flow velocity, not hemoglobin oxygen saturation.

Pulse oximetry = spectrophotometry (red vs infrared absorption) + plethysmography (isolating the pulsatile arterial component).

Answer: B

The ECG lead wires on each of the 16 patients: Lead wires affect local waveforms; the bedside monitors are still showing good signals.

The network switch or central server that links them: Correct. A simultaneous loss of all monitors with intact bedside function points to a shared component, such as the network switch, central server or power to network equipment.

The internal battery in each bedside monitor: Sixteen batteries failing at the same moment is implausible, and the monitors are still running.

The display screen settings on the central station: Display settings would not cause every monitor to lose its connection at once; the data link is the issue.

One device affected suggests a local fault; many devices failing simultaneously suggests a shared system component (network, server, power). Notify clinical staff to monitor at the bedside meanwhile.

Answer: C

DICOM: DICOM is the standard for medical images and related information, such as CT and ultrasound studies.

SMTP: SMTP is an email transfer protocol, not a clinical data messaging standard.

HL7: Correct. Health Level Seven (HL7, e.g., v2 ORU result messages and ADT messages, and FHIR) is the main standard for exchanging clinical data between devices, gateways and the EMR.

SNMP: SNMP manages and monitors network devices; it does not carry patient results to the EMR.

HL7 carries clinical and administrative messages (ADT, orders, results) to and from the EMR; DICOM handles images; ADT feeds also associate devices with the correct patient.