Updated: Dec 9, 2025 | Source: 2024-2028 Question Pool | Topic: E6F
E6F07E6F

What is a solid-state relay?

Deep Dive: E6F07

The correct answer is B: A device that uses semiconductors to implement the functions of an electromechanical relay. What is a solid-state relay is a device that uses semiconductors to implement the functions of an electromechanical relay. Solid-state relays replace mechanical relays with semiconductors. For amateur radio operators, this is important for component knowledge. Understanding this helps when using relays.

Why Other Answers Are Wrong

Option A: Incorrect. Relay using transistors to drive relay coil isn't solid-state relay - solid-state relay uses semiconductors instead of mechanical relay. Transistor-driven coil isn't solid-state. Option C: Incorrect. Mechanical relay that latches isn't solid-state - solid-state relay uses semiconductors instead of mechanical. Mechanical latch isn't solid-state. Option D: Incorrect. Semiconductor switch using monostable multivibrator isn't solid-state relay - solid-state relay uses semiconductors to implement relay functions. Monostable switch isn't the definition.

Exam Tip

Solid-state relay = device using semiconductors to implement electromechanical relay functions. Think 'S'olid-'S'tate 'R'elay = 'S'emiconductors 'R'eplace mechanical. Solid-state relays replace mechanical relays with semiconductors. Not transistor-driven coil, not mechanical latch, not monostable switch - just semiconductors implementing relay functions.

Memory Aid

Solid-state relay = device using semiconductors to implement electromechanical relay functions. Think 'S'olid-'S'tate = 'S'emiconductors. Solid-state relays replace mechanical relays with semiconductors. Important for component knowledge.

Real-World Example

A solid-state relay: It's a device that uses semiconductors to implement the functions of an electromechanical relay. Instead of mechanical contacts, it uses semiconductor switches. This is what it is - semiconductors implementing relay functions.

Source & Coverage

Question Pool: 2024-2028 Question Pool

Subelement: E6F

Reference: 2024-2028 Question Pool · E6 - Circuit Components

Key Concepts

Solid-state relay Device that uses semiconductors Implement functions Electromechanical relay

Verified Content

Question from the official FCC Extra Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the E6F topic.