Which of these is an example of an electric discharge?

Options

A. The charges in a metallic ball falling to the Earth when the ball is touched by a finger
B. Rough tectonic plates slipping past each other releasing tremendous pressure.
C. A spark flying through air between a charged balloon and a glowing bulb.
D. Lightning falling on a lightning conductor flowing towards the ground

Answer

To determine which of the given options is an example of an electric discharge, we first need to understand what electric discharge is.

### Step-by-Step Solution:

1. **Definition of Electric Discharge**:
- Electric discharge occurs when there is a movement of electric charge, typically resulting in the production of bright light and sound. This happens when negative and positive charges come into contact.

2. **Analyzing the Options**:
- **Option 1**: "The charges in a metallic ball falling to the earth when the ball is touched by a finger."
- **Analysis**: In this scenario, there is no production of bright light or sound when the charges in the metallic ball fall to the earth. Therefore, this is not an example of electric discharge.
- **Conclusion**: Incorrect option.

- **Option 2**: "Rough tectonic plates slipping past each other, releasing tremendous pressure."
- **Analysis**: This describes geological activity (earthquakes) and does not involve electric charges or the production of light and sound.
- **Conclusion**: Incorrect option.

- **Option 3**: "A spark flying through air between a charged balloon and a glowing bulb."
- **Analysis**: This scenario involves a spark, which is a clear indication of electric discharge. The spark represents the movement of electric charge and is accompanied by bright light.
- **Conclusion**: Correct option.

- **Option 4**: "Lightning falling on a lightning conductor flowing towards the ground."
- **Analysis**: While lightning is a form of electric discharge, in this case, it is transferring energy to the ground and does not produce a spark in the same way as the previous option. The bright light is not produced in the same context as defined for electric discharge.
- **Conclusion**: Incorrect option.

3. **Final Answer**: The correct example of electric discharge is **Option 3**: "A spark flying through air between a charged balloon and a glowing bulb."