If at a certain place `B_H` and `B_V` are horizontal and vertical components of earth's magnetic field respectively and `delta` is the angle of dip at the same place then

Options

A. `B_V = B_H tan delta `
B. `B_H = B_V tan delta `
C. `B_V = B_Hsin delta`
D. `B_H = B_V cos delta `

Explanation

To solve the problem, we need to establish the relationship between the horizontal component of the Earth's magnetic field (B_H), the vertical component of the Earth's magnetic field (B_V), and the angle of dip (δ).

### Step-by-Step Solution:

1. **Understanding the Components**:
- The Earth's magnetic field can be resolved into two components: the horizontal component (B_H) and the vertical component (B_V).

2. **Defining the Angle of Dip**:
- The angle of dip (δ) is defined as the angle made by the Earth's magnetic field with the horizontal plane.

3. **Using the Tangent of the Angle of Dip**:
- The relationship between the vertical and horizontal components of the magnetic field and the angle of dip is given by the formula:
\[ \tan(\delta) = \frac{B_V}{B_H} \]

4. **Rearranging the Equation**:
- From the above equation, we can express the vertical component in terms of the horizontal component and the angle of dip:
\[ B_V = B_H \tan(\delta) \]

5. **Conclusion**:
- This means that the vertical component of the Earth's magnetic field (B_V) is equal to the horizontal component (B_H) multiplied by the tangent of the angle of dip (δ).

### Final Result:
Thus, the relationship can be summarized as:
\[ B_V = B_H \tan(\delta) \]