Updated: Dec 9, 2025 | Source: 2023-2027 Question Pool | Topic: G4E
G4E09G4E

What is the approximate open-circuit voltage from a fully illuminated silicon photovoltaic cell?

Deep Dive: G4E09

The correct answer is B: 0.5 VDC. The approximate open-circuit voltage from a fully illuminated silicon photovoltaic cell is 0.5 VDC. Silicon solar cells produce about 0.5 volts per cell under full illumination. For amateur radio operators, this helps when designing solar power systems. Understanding this helps when calculating panel voltages.

Why Other Answers Are Wrong

Option A (0.02 VDC): Incorrect. 0.02 volts is way too low - silicon cells produce about 0.5 volts, not 0.02 volts. 0.02V would be unusable. Option C (0.2 VDC): Incorrect. 0.2 volts is too low - silicon cells produce about 0.5 volts, not 0.2 volts. 0.2V is below typical cell voltage. Option D (1.38 VDC): Incorrect. 1.38 volts is too high - silicon cells produce about 0.5 volts, not 1.38 volts. 1.38V would be multiple cells.

Exam Tip

Silicon photovoltaic cell voltage = 0.5 VDC. Think 'S'ilicon 'C'ell = 'S'ingle cell = '0'.5 volts. Silicon solar cells produce approximately 0.5 volts per cell under full illumination. Not 0.02, 0.2, or 1.38 volts - just 0.5 volts per cell.

Memory Aid

Silicon photovoltaic cell voltage = 0.5 VDC. Think 'S'ilicon 'C'ell = 'S'ingle cell = '0'.5 volts. Silicon solar cells produce approximately 0.5 volts per cell under full illumination. Standard cell voltage.

Real-World Example

A single silicon solar cell under full sunlight produces about 0.5 volts open-circuit. A solar panel with 36 cells in series produces about 18 volts (36 × 0.5V). This 0.5 volts per cell is the standard for silicon photovoltaic cells.

Source & Coverage

Question Pool: 2023-2027 Question Pool

Subelement: G4E

Reference: 2023-2027 Question Pool · G4 - Amateur Radio Practices

Key Concepts

Photovoltaic cell Open-circuit voltage 0.5 VDC Solar cell

Verified Content

Question from the official FCC General Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the G4E topic.