In electromagnetic wave, the phase difference between electric and magnetic field vectors E and B is

Options

A. zero
B. `pi//2`
C. `pi`
D. `pi//4`

Answer

To solve the question regarding the phase difference between the electric field vector (E) and the magnetic field vector (B) in an electromagnetic wave, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Electromagnetic Waves**:
Electromagnetic waves consist of oscillating electric (E) and magnetic (B) fields that are perpendicular to each other and to the direction of wave propagation.

2. **Orientation of Fields**:
In an electromagnetic wave, if we assume the electric field (E) oscillates in the xy-plane, the magnetic field (B) will oscillate in the xz-plane. This means that E and B are oriented in different planes but are still related to the same wave.

3. **Analyzing Oscillations**:
Both the electric and magnetic fields oscillate sinusoidally. The peaks (maximum values) and zeros (minimum values) of these oscillations occur at the same time.

4. **Phase Difference Definition**:
The phase difference between two oscillating quantities is defined as the difference in their phases at a given point in time. If the peaks and zeros of the two oscillations occur simultaneously, the phase difference is zero.

5. **Conclusion**:
Since there is no time difference between the peaks of the electric and magnetic oscillations in an electromagnetic wave, the phase difference between the electric field vector (E) and the magnetic field vector (B) is zero.

### Final Answer:
The phase difference between the electric and magnetic field vectors E and B in an electromagnetic wave is **0 degrees**.

---