The RMS value of the electric field of the light coming from a monochromatic light source is 720 N/C. The average total energy density of the electromagnetic wave at this point is:
a) (2.592 × 10⁻⁶ J/m³)
b) (5.184 × 10⁻⁶ J/m³)
c) (7.776 × 10⁻⁶ J/m³)
d) (1.0368 × 10⁻⁵ J/m³)
