The amplitude of em wave in vacuum is doubled with no other changes made to wave. As a result of this doubling of the amplitude, which of the following statement is correct.

Options

A. The speed of wave propagation changes only
B. The frequency of the wave change only
C. The wavelength of the wave changes only
D. None of these

Explanation

To solve the question regarding the effect of doubling the amplitude of an electromagnetic (EM) wave in a vacuum, we will analyze the properties of EM waves and how amplitude relates to other characteristics of the wave.

### Step-by-Step Solution:

1. **Understanding the Properties of EM Waves**:
- An electromagnetic wave is characterized by its amplitude, frequency, wavelength, and speed. The speed of light in a vacuum (c) is given by the equation:
\[ c = \frac{1}{\sqrt{\mu_0 \epsilon_0}} \]
- Here, \(\mu_0\) is the permeability of free space, and \(\epsilon_0\) is the permittivity of free space.

2. **Effect of Doubling the Amplitude**:
- The amplitude of an EM wave represents the maximum strength of the electric and magnetic fields in the wave. When the amplitude is doubled, it means that the maximum electric and magnetic field strengths are increased.

3. **Analyzing the Relationship Between Amplitude and Other Properties**:
- The amplitude does not affect the speed of the wave, which remains constant in a vacuum (c = 3 x 10^8 m/s).
- The frequency of the wave is determined by the source of the wave and is not affected by the amplitude.
- Similarly, the wavelength of the wave is related to the speed and frequency by the equation:
\[ \lambda = \frac{c}{f} \]
- Since neither the speed nor the frequency changes when the amplitude is doubled, the wavelength also remains unchanged.

4. **Conclusion**:
- Since the amplitude is independent of the speed, frequency, and wavelength of the electromagnetic wave, doubling the amplitude does not change any of these properties.
- Therefore, the correct statement regarding the effect of doubling the amplitude of an EM wave in a vacuum is that none of the other properties (speed, frequency, wavelength) change.

### Final Answer:
- The correct statement is: **None of the properties change** (Option D).