In what ways the directions of the electric and magnetic field vectors representing an electromagnetic waves related to each other?

When can a charge act as a source of electromagnetic wave? How are there directions of electric and magneitc field vectors, in an electromagnetic wave related to each other and to the direction of propagation of the wave? Which physical quantity, if any has the same value for waves belonging to the differnt parts of the electromangetic spectrum?

What are electromagnetic waves?

An electromagnetic wave is travelling in a medium with a velocity vecv=v hati . The electric field oscillations, of this electromagnetic wave, all along the Y-axis. How are the magnitude of the electric and magnetic fields in the electromagnetic wave related to each other?

The electric and magnetic fields in an electromagnetic wave are

What are the uses of electromagnetic waves?

What is the speed of electromagnetic wave?

What is the direction of electric field intensity vector vecE ?