Deep Dive: G5C06
The correct answer is A: 360 volts. The voltage output of a transformer with a 500-turn primary and a 1500-turn secondary when 120 VAC is applied to the primary is 360 volts. Turns ratio = 1500/500 = 3:1 (step-up). Output = 120 × 3 = 360V. For amateur radio operators, this is a basic transformer calculation. Understanding this helps when using transformers.
Why Other Answers Are Wrong
Option B (120 volts): Incorrect. 120 volts would be if turns ratio was 1:1, but ratio is 3:1. Output should be 3× input. Option C (40 volts): Incorrect. 40 volts would be if it was step-down (1:3), but it's step-up (3:1). Output should be higher, not lower. Option D (25.5 volts): Incorrect. 25.5 volts is way too low - that doesn't match any reasonable calculation. Calculation error.
Exam Tip
Transformer output: Turns ratio = 1500/500 = 3:1, Output = 120 × 3 = 360V. Think 'T'ransformer = 'T'urns ratio determines 'V'oltage. Output voltage = input voltage × (secondary turns / primary turns). Not 120V, not 40V, not 25.5V - just 360V.
Memory Aid
Transformer output: Turns ratio = 3:1, Output = 120 × 3 = 360V. Think 'T'ransformer = 'T'urns ratio. Output voltage = input voltage × (secondary/primary turns). Standard transformer calculation.
Real-World Example
A transformer: 500-turn primary, 1500-turn secondary. Turns ratio = 1500/500 = 3:1 (step-up). Apply 120V to primary. Output = 120 × 3 = 360 volts. The secondary has 3× the turns, so output is 3× the input voltage.
Source & Coverage
Question Pool: 2023-2027 Question Pool
Subelement: G5C
Reference: 2023-2027 Question Pool · G5 - Electrical Principles
Key Concepts
Verified Content
Question from the official FCC General Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the G5C topic.