Show that the electric field in free space satisfies a wave equation and obtain the speed of propagation of the wave.
a. (i) Starting from the set of fundamental field equations valid in free space (charge-free, current-free region), derive a second-order partial differential equation for the electric field.
b. (ii) Obtain a similar equation for the magnetic field.
c. (iii) Hence deduce that electromagnetic disturbances travel through free space with speed c=1/μ0ε0 and compare this value with the known speed of light in vacuum.