Question

What happens when a slice of potato is connected to an LED and a battery for a long time as shown in the figure below?

• A. A greenish blue spot forms on the potato where wire A is connected.
• B. The LED glows.
• C. A greenish blue spot forms on the potato where wire B is connected.
• D. The LED doesn't glow.

Answer 1

Answer: (B), (C)

The correct options are
B The LED glows.
C A greenish blue spot forms on the potato where wire B is connected.

The salts and minerals present in a potato can conduct electricity. So, a small current flows, making the LED glow. When we leave this arrangement undisturbed for long time, the chemical content in the potato changes and a greenish blue spot forms on it where the wire B, i.e. wire from the positive terminal of the battery is connected.