How is impedance in polar form converted to an equivalent admittance?
The correct answer is B: Take the reciprocal of the magnitude and change the sign of the angle. How is impedance in polar form converted to an equivalent admittance is to take the reciprocal of the magnitude and change the sign of the angle. Admittance is the reciprocal of impedance, so magnitude is reciprocal and angle sign changes. For amateur radio operators, this is important for circuit calculations. Understanding this helps when converting between impedance and admittance.
Exam Tip
Impedance to admittance conversion = reciprocal of magnitude, change sign of angle. Think 'I'mpedance to 'A'dmittance = 'I'nvert 'A'mplitude, 'A'lter angle sign. Admittance is reciprocal of impedance. Not angle/magnitude swap, not square root/180°, not square/90° - just reciprocal magnitude, change angle sign.
Memory Aid
"Impedance to admittance conversion = reciprocal of magnitude, change sign of angle. Think 'I'mpedance to 'A'dmittance = 'R'eciprocal, 'S'ign change. Admittance is reciprocal of impedance. Important for circuit calculations."
Real-World Application
Converting impedance in polar form to equivalent admittance: Take the reciprocal of the magnitude and change the sign of the angle. For example, if Z = 50∠30°, then Y = (1/50)∠-30° = 0.02∠-30°. This is the conversion - reciprocal magnitude, change angle sign.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Reciprocal of angle and change sign of magnitude isn't correct - reciprocal of magnitude and change sign of angle is correct. Angle/magnitude swap is wrong.
Option C: Incorrect. Square root of magnitude and add 180 degrees to angle isn't correct - reciprocal of magnitude and change sign of angle is correct. Square root/180° isn't correct.
Option D: Incorrect. Square magnitude and subtract 90 degrees from angle isn't correct - reciprocal of magnitude and change sign of angle is correct. Square/90° isn't correct.
题目解析
The correct answer is B: Take the reciprocal of the magnitude and change the sign of the angle. How is impedance in polar form converted to an equivalent admittance is to take the reciprocal of the magnitude and change the sign of the angle. Admittance is the reciprocal of impedance, so magnitude is reciprocal and angle sign changes. For amateur radio operators, this is important for circuit calculations. Understanding this helps when converting between impedance and admittance.
考试技巧
Impedance to admittance conversion = reciprocal of magnitude, change sign of angle. Think 'I'mpedance to 'A'dmittance = 'I'nvert 'A'mplitude, 'A'lter angle sign. Admittance is reciprocal of impedance. Not angle/magnitude swap, not square root/180°, not square/90° - just reciprocal magnitude, change angle sign.
记忆口诀
Impedance to admittance conversion = reciprocal of magnitude, change sign of angle. Think 'I'mpedance to 'A'dmittance = 'R'eciprocal, 'S'ign change. Admittance is reciprocal of impedance. Important for circuit calculations.
实际应用示例
Converting impedance in polar form to equivalent admittance: Take the reciprocal of the magnitude and change the sign of the angle. For example, if Z = 50∠30°, then Y = (1/50)∠-30° = 0.02∠-30°. This is the conversion - reciprocal magnitude, change angle sign.
错误选项分析
Option A: Incorrect. Reciprocal of angle and change sign of magnitude isn't correct - reciprocal of magnitude and change sign of angle is correct. Angle/magnitude swap is wrong. Option C: Incorrect. Square root of magnitude and add 180 degrees to angle isn't correct - reciprocal of magnitude and change sign of angle is correct. Square root/180° isn't correct. Option D: Incorrect. Square magnitude and subtract 90 degrees from angle isn't correct - reciprocal of magnitude and change sign of angle is correct. Square/90° isn't correct.
知识点
Impedance in polar form, Converted to equivalent admittance, Reciprocal of magnitude, Change sign of angle
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.