CBET Basic 4

Question 1

What does the term 'impedance' represent in an AC circuit?

Accepted Answer

The total opposition to AC current including resistance, inductance, and capacitance

Answer

Impedance (Z) is the total opposition to AC current flow, combining resistance (R) with reactance (X) from inductors and capacitors.

Question 2

In a hospital power system, what color is the equipment grounding conductor per NEC standards?

Accepted Answer

Green or bare

Answer

Per NEC Article 250, equipment grounding conductors are identified by green insulation, green with yellow stripe, or bare copper.

Question 3

Which physiological signal has the lowest typical amplitude among the following?

Accepted Answer

EEG (electroencephalogram)

Answer

EEG signals are typically in the range of 2–200 μV, which is lower than ECG (~1 mV), EMG (~1–10 mV), and EOG (~100 μV–1 mV).

Question 4

What is the half-value layer (HVL) in radiological physics?

Accepted Answer

The thickness of material needed to reduce radiation intensity by half

Answer

The HVL is the thickness of a specified material that reduces the intensity of ionizing radiation to one-half of its original value.

Question 5

Which component is used to measure very small DC currents in biomedical instruments by converting them to a voltage?

Accepted Answer

Transimpedance amplifier (current-to-voltage converter)

Answer

A transimpedance amplifier uses an op-amp with a feedback resistor to convert input current to an output voltage proportional to that current.

CBET - Certified Biomedical Equipment Technician Practice Test