Question

what is the speed of electromagnetic waves in vacuum?

Answer 1

speed of electromagnetic waves is same as of light cause light is also a electro magnetic wave ( visible light )  that is 3 x10⁸ m/s 

Answer 2

Speed of electromagnetic waves in vacuum is $3*10^{8} m/s^{2}$.

What is an electromagnetic wave?

• An electromagnetic wave needs no medium to travel. There is no requirement of particles for the propagation of wave.
• These waves can travel through space and vacuum.
• These waves carry €radiant energies.
• Electromagnetic waves are created by vibration of magnetic and electric field in mutually perpendicular direction.
• Direction of wave propagation is normal to electric and magnetic field.
• Light is an electromagnetic wave. Velocity of electromagnetic wave is same as light i.e. $3*10^{8} m/s^{2}$.