Electrical Comprehension DAA Practice Test

In bright light, what happens to the resistance of an LDR?

High Zero Infinite Low

Correct Answer:

Low

Explanation:

Light affects how well the material conducts electricity. An LDR is a semiconductor whose conductivity rises when illuminated. When bright light shines on it, photons generate more free charge carriers (electrons and holes), so the material conducts better. For a given applied voltage, more current flows, which means the resistance drops. It isn’t literally zero or infinite in normal conditions, but it becomes much lower than in darkness. That’s why the correct choice is that the resistance is low in bright light.

Access more questions from this quiz

Continue to Electrical Comprehension DAA Practice Test for more practice questions and the full quiz experience.

Access More Questions