Electronics and Electrical Safety Flashcards
7 cards from real CBET practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Electronics and Electrical Safety flashcards as text
When testing electrical safety with a safety analyzer, the 'patient lead to ground' leakage test measures current flowing from:
Answer: Applied parts to the equipment ground
Patient lead-to-ground leakage measures current that could flow through a patient from applied parts to ground, reflecting direct patient risk.
What is the function of a decoupling capacitor placed near an IC power pin?
Answer: Filter high-frequency noise on the supply rail
Decoupling capacitors suppress high-frequency transients and noise on the supply voltage rail, stabilizing IC operation.
An op-amp configured with the non-inverting input connected to a voltage divider and output fed back to the inverting input is functioning as a:
Answer: Voltage follower (buffer)
When the output feeds directly back to the inverting input with no other feedback components, the op-amp becomes a unity-gain voltage follower.
Which condition does a Line Isolation Monitor (LIM) detect in an isolated power system?
Answer: First fault to ground in the isolated circuit
A LIM continuously monitors the impedance from the isolated conductors to ground and alarms when the first fault reduces isolation below safe limits.
In a full-wave bridge rectifier with four diodes, the output ripple frequency relative to the AC input frequency is:
Answer: Double (2×)
A full-wave bridge rectifier conducts on both half-cycles, producing two output pulses per input cycle, doubling the ripple frequency.
According to electrical safety standards, the ground wire in a medical device power cord must be:
Answer: The same gauge as the hot conductor
The equipment ground conductor must be at least the same gauge as the current-carrying conductors to safely carry fault current.
Thermal runaway in a bipolar junction transistor (BJT) is caused by:
Answer: Positive feedback between temperature rise and collector current increase
As a BJT heats up, leakage current increases, raising collector current which generates more heat, creating a destructive positive feedback loop.