Updated: Dec 9, 2025 | Source: 2024-2028 Question Pool | Topic: E5A
E5A07E5A

What is the magnitude of the current at the input of a parallel RLC circuit at resonance?

Deep Dive: E5A07

The correct answer is A: Minimum. What is the magnitude of the current at the input of a parallel RLC circuit at resonance is minimum. At parallel resonance, input current is minimum (impedance is maximum). For amateur radio operators, this is important for circuit theory. Understanding this helps when working with resonant circuits.

Why Other Answers Are Wrong

Option B (Maximum): Incorrect. Maximum isn't correct - at parallel resonance, input current is minimum. Maximum is wrong. Option C (R/L): Incorrect. R/L isn't the answer - input current is minimum at resonance. R/L isn't the answer. Option D (L/R): Incorrect. L/R isn't the answer - input current is minimum at resonance. L/R isn't the answer.

Exam Tip

Parallel RLC input current at resonance = minimum. Think 'P'arallel 'R'LC at 'R'esonance = 'M'inimum 'I'nput current. At parallel resonance, input current is minimum (impedance is maximum). Not maximum, not R/L, not L/R - just minimum.

Memory Aid

Parallel RLC input current at resonance = minimum. Think 'P'arallel 'R'LC = 'M'inimum input. At parallel resonance, input current is minimum (impedance is maximum). Important for circuit theory.

Real-World Example

A parallel RLC circuit at resonance: The current at the input is minimum. This is because at parallel resonance, the impedance is maximum, so for a given voltage, the current is minimum. This is the magnitude - minimum input current.

Source & Coverage

Question Pool: 2024-2028 Question Pool

Subelement: E5A

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

Key Concepts

Current at input Parallel RLC circuit At resonance Minimum

Verified Content

Question from the official FCC Extra Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the E5A topic.