Red Seal Electrician Practice
Wiring and componentsQuestion 61 of 1506

Which switch can detect people entering a dangerous area using beams of light?

  1. A speed switch
  2. A temperature switch
  3. A magnetic reed switch
  4. An optical switch
Show answer

Correct answer: An optical switch

Optical switches use a light source and photocell to detect the beam being interrupted or reflected.

Source: Lessons in Electric Circuits IV: Digital (Kuphaldt), 4.1: Switch Types

Practice wiring and components

Questions last reviewed: 18 October 2026