Lesson: Chapter 11 — Electronics

LEDs and solar cells 2 of 4 Reset answers

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Question 2

Why is a red LED not lit by a single 1.5 V cell?

A The cell is too strong B LEDs need alternating current C LEDs work only in reverse D 1.5 V is below its minimum forward voltage of about 1.8 V

The right answer is the one marked above.

1.5 V is below its minimum forward voltage of about 1.8 V. Two cells in series give 3 V, which is enough.

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