Which type of waves do not require a material medium for propagation?

Which type of waves do not require a material medium for their propagation ?

Which of the following waves do not require material medium for propagation?

Which of the following waves does not require any material medium for their propagation?

Which waves do not require medium for propagation?

Which of the following waves does not require any medium for its propagation

Answer the following. : With neat diagram, describe experimental verufication that sound requires a material medium for its propagation.

(A) : The microwaves are better carriers of signals than radio waves. (R) : The electromagnetic waves do not require any medium for propagation.