If `E` and `B` represent electric and magnetic field vectors of the electromagnetic wave, the direction of propagation of eletromagnetic wave is along.

Options

A. E
B. B
C. `Bxx E`
D. `Exx B`

Explanation

To determine the direction of propagation of an electromagnetic wave given the electric field vector \( \mathbf{E} \) and the magnetic field vector \( \mathbf{B} \), we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Vectors**:
- The electric field vector \( \mathbf{E} \) and the magnetic field vector \( \mathbf{B} \) are both perpendicular to each other in an electromagnetic wave.

2. **Direction of Propagation**:
- The direction of propagation of the electromagnetic wave is perpendicular to both \( \mathbf{E} \) and \( \mathbf{B} \).

3. **Using the Right-Hand Rule**:
- To find the direction of propagation, we can use the right-hand rule. If you point your thumb in the direction of \( \mathbf{E} \) and your index finger in the direction of \( \mathbf{B} \), your middle finger will point in the direction of propagation of the wave.

4. **Cross Product**:
- Mathematically, the direction of propagation can be represented by the cross product of the electric field vector \( \mathbf{E} \) and the magnetic field vector \( \mathbf{B} \). Thus, the direction of propagation \( \mathbf{k} \) can be expressed as:
\[ \mathbf{k} \propto \mathbf{E} \times \mathbf{B} \]
- This indicates that the wave propagates in a direction that is perpendicular to both \( \mathbf{E} \) and \( \mathbf{B} \).

5. **Conclusion**:
- Therefore, the direction of propagation of the electromagnetic wave is given by the expression \( \mathbf{E} \times \mathbf{B} \).

### Final Answer:
The direction of propagation of the electromagnetic wave is along \( \mathbf{E} \times \mathbf{B} \).

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