CBET Electronics and Electrical Safety 4

Question 1

What is the maximum allowable chassis leakage current for a patient-connected device in a general care area according to NFPA 99?

Accepted Answer

100 µA

Answer

NFPA 99 limits chassis leakage current to 100 µA for patient-connected equipment in general care areas.

Question 2

A Zener diode is primarily used in electronic circuits to:

Accepted Answer

Regulate voltage

Answer

Zener diodes operate in reverse breakdown to maintain a stable reference voltage, making them ideal for voltage regulation.

Question 3

Which type of transformer configuration is used in medical-grade isolated power systems to prevent shock hazard?

Accepted Answer

Isolation transformer

Answer

Isolation transformers break the galvanic connection between utility power and the patient care area, preventing ground-fault shock.

Question 4

In a series RLC circuit at resonance, the impedance is:

Accepted Answer

Minimum and purely resistive

Answer

At resonance, XL and XC cancel each other, leaving only resistance, so impedance is at its minimum and purely resistive.

Question 5

What does the term 'macroshock' refer to in electrical safety?

Accepted Answer

Large current entering the body through the skin

Answer

Macroshock involves relatively large currents (milliamps) applied externally to the body, typically causing ventricular fibrillation at 100 mA.

CBET - Certified Biomedical Equipment Technician Practice Test