During electrolysis, which of the following indicates that current is flowing?

• A. The bulb will light
• B. The lamp remains off
• C. The solution becomes cloudy
• D. The electrodes melt

Answer: (A)

The main idea here is that current flow in an electrolysis setup shows up by energy being delivered to a device in the circuit. When the circuit is complete and electrons are moving, a connected bulb will light because electrical energy is being converted into light. So, seeing the bulb glow is a direct sign that current is flowing.

If the lamp stays off, there isn’t current flowing, meaning the circuit isn’t closed or the electrolyte isn’t conducting. Changes like the solution becoming cloudy are related to chemical reactions at the electrodes, not a direct indication of current. Melting electrodes would point to excessive current and overheating, which is not a normal indication of current flow.