Question

Speed of electromagnetic waves is the same

• A. For all wavelengths
• B. In all media
• C. For all intensities
• D. For all frequencies

Answer 1

The correct option is C For all intensities

As we know electromagnetic wave travels with speed of light.
So we have a relation as
$c=\nu \lambda$
where symbols have their usual meaning.
Now as we can see that speed depends upon frequency and wavelength, then option(a) and option(d) are directly eleminated.
For option(b), if medium changes then it would affect the wavelength of the wave and hence indirectly affecting speed. So option(b) is also incorrect.
Option(c) does not affect the speed of light.