The lines joining the places of the same horizontal intensity are known as

Options

A. Isogonic lines
B. Aclinic lines
C. Isoclinic lines
D. Isodynamic lines

Answer

To solve the question, we need to understand the concept of lines that represent places with the same horizontal intensity in the context of magnetism.

### Step-by-step Solution:

1. **Understanding Magnetic Intensity**:
- Magnetic intensity refers to the strength of the magnetic field at a given point in space. It can vary from one location to another.

2. **Definition of Iso-dynamic Lines**:
- The lines that connect points where the magnetic intensity is the same are known as iso-dynamic lines. These lines help in visualizing the distribution of magnetic intensity in a particular area.

3. **Horizontal Intensity**:
- The term "horizontal intensity" specifically refers to the component of the magnetic field that is parallel to the Earth's surface.

4. **Conclusion**:
- Therefore, the lines that join places of the same horizontal magnetic intensity are called **iso-dynamic lines**.

### Final Answer:
The lines joining the places of the same horizontal intensity are known as **iso-dynamic lines**.

---