What type of transistor has a gate, drain, and source?
The correct answer is B: Field-effect. A Field-effect transistor (FET) is the type of transistor that has a gate, drain, and source. These are the three terminals of a FET, corresponding to the base, collector, and emitter of a bipolar transistor.
Field-effect transistors (FETs) have three terminals: gate (control), drain (output), and source (input). The gate controls current flow between source and drain through an electric field (hence 'field-effect'). FETs include MOSFETs (Metal-Oxide-Semiconductor FETs) and JFETs (Junction FETs). They're voltage-controlled devices (gate voltage controls drain-source current), unlike bipolar transistors which are current-controlled. FETs are widely used in amplifiers, switches, and digital circuits.
Exam Tip
FET = Gate, drain, source. Remember: Field-effect transistors (FETs) have gate, drain, and source terminals - these are the three terminals of a FET.
Memory Aid
"**F**ET = **G**ate, **D**rain, **S**ource (think 'FET = GDS')"
Real-World Application
You're working with a MOSFET (a type of FET) in an amplifier circuit. It has three terminals: gate (control input), drain (output), and source (common). The gate voltage controls current flow between source and drain. This is the structure of all field-effect transistors.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Varistors are voltage-dependent resistors, not transistors. They don't have gate, drain, and source terminals - they're two-terminal devices.
Option C: Incorrect. Tesla-effect is not a real transistor type. This is a distractor - there's no such thing as a Tesla-effect transistor.
Option D: Incorrect. Bipolar junction transistors (BJTs) have emitter, base, and collector terminals, not gate, drain, and source. Gate/drain/source are FET terminals.
题目解析
The correct answer is B: Field-effect. A Field-effect transistor (FET) is the type of transistor that has a gate, drain, and source. These are the three terminals of a FET, corresponding to the base, collector, and emitter of a bipolar transistor. Field-effect transistors (FETs) have three terminals: gate (control), drain (output), and source (input). The gate controls current flow between source and drain through an electric field (hence 'field-effect'). FETs include MOSFETs (Metal-Oxide-Semiconductor FETs) and JFETs (Junction FETs). They're voltage-controlled devices (gate voltage controls drain-source current), unlike bipolar transistors which are current-controlled. FETs are widely used in amplifiers, switches, and digital circuits.
考试技巧
FET = Gate, drain, source. Remember: Field-effect transistors (FETs) have gate, drain, and source terminals - these are the three terminals of a FET.
记忆口诀
**F**ET = **G**ate, **D**rain, **S**ource (think 'FET = GDS')
实际应用示例
You're working with a MOSFET (a type of FET) in an amplifier circuit. It has three terminals: gate (control input), drain (output), and source (common). The gate voltage controls current flow between source and drain. This is the structure of all field-effect transistors.
错误选项分析
Option A: Incorrect. Varistors are voltage-dependent resistors, not transistors. They don't have gate, drain, and source terminals - they're two-terminal devices. Option C: Incorrect. Tesla-effect is not a real transistor type. This is a distractor - there's no such thing as a Tesla-effect transistor. Option D: Incorrect. Bipolar junction transistors (BJTs) have emitter, base, and collector terminals, not gate, drain, and source. Gate/drain/source are FET terminals.
知识点
Field-effect transistor, FET, Gate, drain, source, Semiconductor devices
Verified Content
Question from official FCC Technician Class question pool. Explanation reviewed by licensed amateur radio operators.