Which of these is a correct description of how lightning occurs?

Options

A. The Earth develops a positive charge, which induces a negative charge on the bottom of clouds.
B. The Earth develops a negative charge, which induces a positive charge on the bottom of clouds.
C. The bottom surface of clouds develops a negative charge, which induces a positive charge on the Earth.
D. The bottom surface of clouds develops a positive charge, which induces a negative charge on the Earth.

Answer

**Step-by-Step Solution:**

1. **Understanding Lightning:**
- Lightning is a natural phenomenon that occurs due to the discharge of electricity in the atmosphere. It is primarily caused by the buildup of electrical charges within clouds.

2. **Charge Distribution:**
- In a thunderstorm, the bottom of the cloud accumulates negative charges. This is where the negative charge is concentrated.

3. **Induction of Charges:**
- The negative charges at the bottom of the cloud attract positive charges from the ground. This means that the ground develops a positive charge due to the influence of the negative charges in the cloud.

4. **Lightning Occurrence:**
- When the difference in charge becomes significant, a discharge occurs, resulting in lightning. This discharge happens as the negative charges from the cloud move towards the positive charges on the ground.

5. **Analyzing the Options:**
- **Option 1:** "The earth develops a positive charge, which induces a negative charge on the bottom of the cloud." - This is incorrect because it reverses the actual process.
- **Option 2:** "The earth develops a negative charge." - This is incorrect as the earth develops a positive charge.
- **Option 3:** "The bottom surface of the clouds develops a negative charge, which induces a positive charge on the earth." - This is correct as it accurately describes the process.
- **Option 4:** "The bottom surface of the cloud develops a positive charge." - This is incorrect because the bottom of the cloud actually develops a negative charge.

6. **Conclusion:**
- The correct description of how lightning occurs is given by **Option 3**: "The bottom surface of the clouds develops a negative charge, which induces a positive charge on the earth."

---