*Question E3A05:
How are the component fields of an electromagnetic wave oriented?*  

*Correct Answer is  C: They are at right angles*  

### AI Response: (may contain errors)  

The correct answer to the question about the orientation of the component fields of an electromagnetic wave is:

**C: They are at right angles.**

### Explanation:

1. **Why the correct answer is correct:**
   - In an electromagnetic wave, the electric field (E) and the magnetic field (B) are oriented at right angles (90 degrees) to each other and also to the direction of wave propagation. This is a fundamental characteristic of electromagnetic waves, as described by Maxwell's equations. The relationship can be visualized as follows:
     - If the wave is traveling in the z-direction, the electric field might oscillate in the x-direction, and the magnetic field would oscillate in the y-direction. Thus, we have:
       - $E \perp B \perp \text{direction of propagation}$.

2. **Why the other choices are incorrect:**
   - **A: They are parallel.**
     - This is incorrect because the electric and magnetic fields cannot be parallel; they must be perpendicular to each other.
   - **B: They are tangential.**
     - This is also incorrect. Tangential implies that the fields would be along the same line or curve, which contradicts the perpendicular nature of the fields in an electromagnetic wave.
   - **D: They are 90 degrees out of phase.**
     - While the electric and magnetic fields are indeed 90 degrees out of phase in terms of their oscillation, this choice does not accurately describe their spatial orientation. The correct description of their orientation is that they are at right angles to each other, not out of phase.

### Useful Concepts:
- **Maxwell's Equations:** These equations describe how electric and magnetic fields propagate and interact. They confirm that in free space, the fields are perpendicular.
- **Wave Propagation:** The direction of wave propagation is always perpendicular to both the electric and magnetic fields.

Understanding these relationships is crucial for grasping the behavior of electromagnetic waves, which is a key concept in amateur radio and many other fields of physics and engineering.