Answer:
the branch of mechanics concerned with the interaction of electric currents with magnetic fields or with other electric currents.
Explanation:
the state of being thick, sticky, and semifluid in consistency, due to internal friction.
Answer:
and 
Explanation:
The wavelength of a visible light is 727.3 nm.

The formula is as follows :

f is the frequency of the visible light

Energy of a photon is given by :
E = hf, h is Planck's constant

Red color has a frequency of
and energy per photon is
.
It is important to note that the electromagnetic spectrum has a variety of wavelength and frequency of light in it. Some lights we can see, while others are not visual to our naked eye. It is actually very important to determine the kind of light as different lights have different wavelengths and frequencies. some lights are of very high frequency like the gamma rays, while others are of far lower frequency. <span />