What are electromagnetic radiations? What is their velocity in vacuum?

What is electromagnetic radiation?

What is electromagnetic radiation ?

What is the velocity of sound in vacuum?

What are electromagnetic radiations ? Name two such radiations.

Which of the following types of electromagnetic radiation travels at the greatest speed in vacuum ?

The wavelength of an electromagnetic radiation is lamda . What is the energy of a photon of this radiation?

What are the properties of electromagnetic radiations?