Deep Dive: E6A09
The correct answer is A: An FET that exhibits a current flow between source and drain when no gate voltage is applied. What is a depletion-mode field-effect transistor (FET) is an FET that exhibits a current flow between source and drain when no gate voltage is applied. Depletion-mode FETs conduct with zero gate voltage. For amateur radio operators, this is important for transistor knowledge. Understanding this helps when working with FETs.
Why Other Answers Are Wrong
Option B: Incorrect. No current flow when no gate voltage isn't depletion-mode - that's enhancement-mode. No current isn't depletion-mode. Option C: Incorrect. Very high electron mobility isn't the definition - depletion-mode conducts with zero gate voltage. Electron mobility isn't the definition. Option D: Incorrect. Holes as majority carriers isn't the definition - depletion-mode conducts with zero gate voltage. Holes isn't the definition.
Exam Tip
Depletion-mode FET = conducts with no gate voltage. Think 'D'epletion-'M'ode = 'D'efault 'M'ode (conducts). Depletion-mode FETs conduct with zero gate voltage. Not no current (enhancement-mode), not electron mobility, not holes - just conducts with zero gate voltage.
Memory Aid
Depletion-mode FET = conducts with no gate voltage. Think 'D'epletion-'M'ode = 'C'onducts 'D'efault. Depletion-mode FETs conduct with zero gate voltage. Important for transistor knowledge.
Real-World Example
A depletion-mode field-effect transistor: It's an FET that exhibits a current flow between source and drain when no gate voltage is applied. Depletion-mode FETs are normally on and require gate voltage to turn off. This is what it is - conducts with no gate voltage.
Source & Coverage
Question Pool: 2024-2028 Question Pool
Subelement: E6A
Reference: 2024-2028 Question Pool · E6 - Circuit Components
Key Concepts
Verified Content
Question from the official FCC Extra Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the E6A topic.