Why should wire-wound resistors not be used in RF circuits?
The correct answer is B: The resistor's inductance could make circuit performance unpredictable. Why wire-wound resistors should not be used in RF circuits is that the resistor's inductance could make circuit performance unpredictable. Wire-wound resistors have significant inductance that affects RF operation. For amateur radio operators, this is important for RF circuit design. Understanding this helps when selecting resistors.
Exam Tip
Don't use wire-wound in RF = inductance makes performance unpredictable. Think 'W'ire-'W'ound = 'W'inding creates 'I'nductance. Wire-wound resistors have significant inductance that affects RF operation. Not tolerance, not overheating, not capacitance - just inductance.
Memory Aid
"Don't use wire-wound in RF = inductance makes performance unpredictable. Think 'W'ire-'W'ound = 'W'inding creates 'I'nductance. Wire-wound resistors have significant inductance that affects RF operation. Use carbon or metal film for RF."
Real-World Application
You design an RF circuit. Wire-wound resistors have significant inductance from their coil construction, which can resonate with circuit capacitance or affect impedance at RF frequencies. This makes circuit performance unpredictable. Use carbon or metal film resistors for RF instead.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Tolerance isn't the issue - wire-wound resistors can have good tolerance. The issue is inductance, not tolerance.
Option C: Incorrect. Overheating isn't the specific issue - wire-wound resistors can handle power. The issue is inductance affecting RF performance.
Option D: Incorrect. Internal capacitance isn't the issue - the issue is inductance. Wire-wound resistors have inductance, not problematic capacitance.
题目解析
The correct answer is B: The resistor's inductance could make circuit performance unpredictable. Why wire-wound resistors should not be used in RF circuits is that the resistor's inductance could make circuit performance unpredictable. Wire-wound resistors have significant inductance that affects RF operation. For amateur radio operators, this is important for RF circuit design. Understanding this helps when selecting resistors.
考试技巧
Don't use wire-wound in RF = inductance makes performance unpredictable. Think 'W'ire-'W'ound = 'W'inding creates 'I'nductance. Wire-wound resistors have significant inductance that affects RF operation. Not tolerance, not overheating, not capacitance - just inductance.
记忆口诀
Don't use wire-wound in RF = inductance makes performance unpredictable. Think 'W'ire-'W'ound = 'W'inding creates 'I'nductance. Wire-wound resistors have significant inductance that affects RF operation. Use carbon or metal film for RF.
实际应用示例
You design an RF circuit. Wire-wound resistors have significant inductance from their coil construction, which can resonate with circuit capacitance or affect impedance at RF frequencies. This makes circuit performance unpredictable. Use carbon or metal film resistors for RF instead.
错误选项分析
Option A: Incorrect. Tolerance isn't the issue - wire-wound resistors can have good tolerance. The issue is inductance, not tolerance. Option C: Incorrect. Overheating isn't the specific issue - wire-wound resistors can handle power. The issue is inductance affecting RF performance. Option D: Incorrect. Internal capacitance isn't the issue - the issue is inductance. Wire-wound resistors have inductance, not problematic capacitance.
知识点
Wire-wound resistors, Inductance, RF circuits, Resistor types
Verified Content
Question from official FCC General Class question pool. Explanation reviewed by licensed amateur radio operators.