CBET Basic 2 — Questions and Answers
Question 1: Which type of current flows in only one direction through a circuit?
- Alternating current (AC)
- Direct current (DC) (Correct answer)
- Pulsed current
- Reactive current
Correct answer: Direct current (DC)
Direct current (DC) flows in a single, constant direction, unlike AC which reverses direction periodically.
Question 2: What is the unit of electrical resistance?
- Farad
- Henry
- Ohm (Correct answer)
- Siemens
Correct answer: Ohm
The ohm (Ω) is the SI unit of electrical resistance, named after Georg Simon Ohm.
Question 3: In a parallel circuit, what remains the same across all branches?
- Current
- Resistance
- Power
- Voltage (Correct answer)
Correct answer: Voltage
In a parallel circuit, all branches share the same voltage, while current may differ in each branch.
Question 4: What does a capacitor store?
- Magnetic energy
- Electrical charge (Correct answer)
- Mechanical energy
- Chemical energy
Correct answer: Electrical charge
A capacitor stores electrical charge (and thus energy) in an electric field between its plates.
Question 5: Which standard organization publishes guidelines for medical device electrical safety in the US?
- OSHA
- EPA
- AAMI (Correct answer)
- NIST
Correct answer: AAMI
The Association for the Advancement of Medical Instrumentation (AAMI) publishes standards for medical device safety including AAMI ES60601.
Question 6: The microampere (μA) is equal to how many amperes?
- 10⁻³ A
- 10⁻⁶ A (Correct answer)
- 10⁻⁹ A
- 10⁻¹² A
Correct answer: 10⁻⁶ A
One microampere equals 10⁻⁶ amperes, which is the range relevant to leakage current limits for patient-connected devices.
Question 7: What is the primary purpose of an isolation transformer in a medical environment?
- Step up voltage to power large equipment
- Prevent ground-loop interference in audio systems
- Isolate patients from line voltage ground faults (Correct answer)
- Reduce power consumption of connected devices
Correct answer: Isolate patients from line voltage ground faults
Isolation transformers break the direct connection to earth ground, protecting patients from electric shock if a line fault occurs.
CBET Basic 2
Which type of current flows in only one direction through a circuit?