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

Velocity of electromagnetic wave 

$c=\frac{1}{\sqrt{{\mu }_0{\epsilon }_0}}=3\times {10}^8 {\mathrm{ms}}^{-1}$

The velocity, frequency and wavelength of electromagnetic wave do not depend on the amplitude of the wave, therefore, none of the parameters will change if amplitude is doubled.