CBET General Practice 4

Question 1

A hospital's isolated power system (IPS) is designed primarily to protect against:

Accepted Answer

Macroshock from single-fault ground currents in wet locations

Answer

An IPS isolates the patient care circuit from ground so a single fault does not create a complete circuit for dangerous ground currents (macroshock).

Question 2

When testing a line isolation monitor (LIM), the alarm should activate when the hazard current exceeds:

Accepted Answer

5 mA

Answer

NFPA 99 requires the LIM alarm to activate when total hazard current reaches 5 mA, indicating the IPS isolation has degraded to a dangerous level.

Question 3

A technician notices the hospital's oxygen wall outlet delivers flow but at a lower pressure than specification. The MOST likely cause is:

Accepted Answer

Excessive demand from too many simultaneous users on that zone

Answer

Excessive simultaneous demand on a piped medical gas zone creates a pressure drop due to flow resistance in the supply piping.

Question 4

In a digital-to-analog converter (DAC) used in medical equipment, increasing the bit resolution from 8-bit to 12-bit:

Accepted Answer

Increases the number of discrete output levels from 256 to 4,096

Answer

An 8-bit DAC produces 2^8 = 256 levels while a 12-bit DAC produces 2^12 = 4,096 levels, providing finer output resolution.

Question 5

A technician is performing annual PM on a hospital bed. Which safety check is MOST critical for patient fall prevention?

Accepted Answer

Testing siderail locking mechanisms for secure engagement

Answer

Siderail locking mechanism failure is directly linked to patient falls, making it the highest-priority safety check during hospital bed PM.

CBET - Certified Biomedical Equipment Technician Practice Test