An isotropic point source emits light at wavelength 500 nm, at the rate of 185 W. A light detector is positioned 380 m from the source. What is the maximum rate ∂B/∂t at which the magnetic component of the light changes with time at the detector's location?

Explanation:

Given that

An isotropic point source emits light at a wavelength = 500 nm

Power = 185 W

Radius = 380 m

Let's first calculate the The intensity  of the wave , which is =

=

=  

=

Now;

The amplitude of the magnetic field is calculated afterwards by using poynting vector

i.e

The magnetic field wave equation can now be expressed as;

Taking the differentiation

The maximum value ;

where ;

then

the moon affects the earth gravitation ally, causing certain motions of that body and also producing tides in its ocean and atmosphere. the tidal wave in our atmosphere is, however, far too minute to be an effective cause in any known meteorological phenomenon.

explanation: