CBET Ultimate 2 — Questions and Answers
Question 1: A patient monitor displays an ECG waveform with excessive 60 Hz interference. What is the FIRST troubleshooting step?
- Replace the ECG cable
- Check patient lead connections and skin preparation (Correct answer)
- Replace the monitor
- Recalibrate the amplifier
Correct answer: Check patient lead connections and skin preparation
Poor electrode contact and skin preparation are the most common causes of 60 Hz artifact before replacing hardware.
Question 2: Which regulatory body requires biomedical equipment technicians to maintain a preventive maintenance program in US hospitals?
- FDA
- OSHA
- The Joint Commission (TJC) (Correct answer)
- EPA
Correct answer: The Joint Commission (TJC)
The Joint Commission requires healthcare organizations to maintain an equipment management program including preventive maintenance.
Question 3: A defibrillator delivers energy via a capacitor. If the capacitor stores 360 J but only 200 J is delivered, what happened to the remaining energy?
- It was absorbed by the patient's skin
- It was dissipated as heat in the inductor and internal resistance (Correct answer)
- It was reflected back into the power supply
- It was lost due to electrode impedance mismatch only
Correct answer: It was dissipated as heat in the inductor and internal resistance
Energy not delivered to the patient is dissipated as heat within the discharge circuit components including the inductor and internal resistance.
Question 4: What is the purpose of isolation transformers in patient care areas?
- To increase voltage for medical equipment
- To reduce power consumption
- To prevent line-to-ground shock hazards in wet environments (Correct answer)
- To eliminate harmonic distortion
Correct answer: To prevent line-to-ground shock hazards in wet environments
Isolation transformers break the direct connection to earth ground, preventing current flow through a patient in the event of a single fault.
Question 5: A ventilator's flow sensor reads inconsistently. Which component is MOST likely causing this in a heated wire flow sensor?
- Broken inspiratory valve
- Contamination or condensation on the sensing element (Correct answer)
- Faulty pressure transducer
- Worn compressor bearings
Correct answer: Contamination or condensation on the sensing element
Moisture and secretions contaminating the heated wire element disrupt thermal dissipation, causing inaccurate flow readings.
Question 6: According to NFPA 99, which category of electrical system must power life-safety equipment within 10 seconds of a power outage?
- Category 1 (Essential Electrical System - Life Safety Branch) (Correct answer)
- Category 2 (Critical Branch)
- Category 3 (Equipment Branch)
- Category 4 (General Power)
Correct answer: Category 1 (Essential Electrical System - Life Safety Branch)
NFPA 99 requires the Life Safety Branch of the Essential Electrical System to restore power within 10 seconds via emergency generators.
Question 7: What does a line isolation monitor (LIM) alarm indicate in an OR?
- Total power failure in the isolated power system
- The hazard current from line-to-ground fault has reached a threshold (typically 2 mA) (Correct answer)
- Excessive voltage on the isolated circuit
- A ground wire is broken
Correct answer: The hazard current from line-to-ground fault has reached a threshold (typically 2 mA)
A LIM continuously monitors impedance between each line and ground, alarming when leakage current approaches 2 mA, indicating a first-fault condition.
CBET Ultimate 2
A patient monitor displays an ECG waveform with excessive 60 Hz interference.
What is the FIRST troubleshooting step?