32. Electromagnetic Waves

What is the intensity of an electromagnetic wave with a peak electric field strength of $125V/m$? (Assume the wave is in vacuum and use $c=3.00\times {10}^{8}m/s$ and $\epsilon 0_{}=8.85\times {10}^{-}C{2}^{/}$)

A point source light bulb emits uniformly in all directions with a total power output of $60W$. At a distance of $2.0m$ from the bulb, what is the light intensity?

If a microwave oven operates at a frequency of $2.4\times 109^{\mathrm{Hz}}$ and the intensity inside the oven is $2800 W/m^2$, what is the amplitude of the electric field of the microwaves inside the oven? (Assume the speed of light $c=3.0\times 108^m/s$ and vacuum permittivity $\epsilon =8.85\times 10{-12}^F/m$.)

A 100 W lightbulb actually emits around only 10 W of light. What is the intensity of the light 1 cm away if the light is emitted perfectly spherically? What is the magnitude of the electric field emitted by the lightbulb? What about the magnetic field?