Updated: Dec 9, 2025 | Source: 2024-2028 Question Pool | Topic: E5B
E5B05E5B

What is the effect on the magnitude of pure reactance when it is converted to susceptance?

Deep Dive: E5B05

The correct answer is D: It is replaced by its reciprocal. What is the effect on the magnitude of pure reactance when it is converted to susceptance is that it is replaced by its reciprocal. Susceptance B = 1/X, so the magnitude becomes the reciprocal. For amateur radio operators, this is important for circuit theory. Understanding this helps when converting between reactance and susceptance.

Why Other Answers Are Wrong

Option A: Incorrect. It is unchanged isn't correct - reactance magnitude is replaced by its reciprocal. Unchanged is wrong. Option B: Incorrect. The sign is reversed isn't the effect - the magnitude is replaced by its reciprocal. Sign reversal isn't the effect. Option C: Incorrect. It is shifted by 90 degrees isn't the effect - the magnitude is replaced by its reciprocal. 90° shift isn't the effect.

Exam Tip

Pure reactance to susceptance = magnitude replaced by its reciprocal. Think 'R'eactance to 'S'usceptance = 'R'eciprocal. Susceptance B = 1/X, so magnitude becomes reciprocal. Not unchanged, not sign reversed, not 90° shift - just replaced by reciprocal.

Memory Aid

Pure reactance to susceptance = magnitude replaced by its reciprocal. Think 'R'eactance to 'S'usceptance = 'R'eciprocal. Susceptance B = 1/X, so magnitude becomes reciprocal. Important for circuit theory.

Real-World Example

Converting pure reactance to susceptance: The effect on the magnitude is that it is replaced by its reciprocal. For example, if X = 100 ohms, then B = 1/100 = 0.01 siemens. The magnitude becomes the reciprocal. This is the effect - replaced by its reciprocal.

Source & Coverage

Question Pool: 2024-2028 Question Pool

Subelement: E5B

Reference: 2024-2028 Question Pool · E5 - Electrical Principles

Key Concepts

Magnitude of pure reactance Converted to susceptance Replaced by its reciprocal Reactance to susceptance

Verified Content

Question from the official FCC Extra Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the E5B topic.