A charged particle oscillates about its mean equilibrium position with a frequency of 10⁹ Hz. What is the frequency of the electromagnetic waves produced by the oscillator?

Which mode of propagation is used by short wave broadcast services ?

Which basic mode of communication is used in satellite communication? What type of wave propagation is used in this mode? Write, giving reason, the frequency range used in this mode of propagation.

(a) Why are infra-red waves often called heat waves ? Explain.

(b) What do you understand by the statement, ‘‘Electromagnetic waves transport momentum’’ ?

A laser beam has intensity 2.5 × 10¹⁴ W m^–2. Find the amplitudes of electric and magnetic fields in the beam.

Which of the following have zero average value in a plane electromagnetic wave?

Speed of electromagnetic waves is the same

Consider the following two statements regarding a linearly polarized, plane electromagnetic wave:

(A) The electric field and the magnetic field have equal average values.

(B) The electric energy and the magnetic energy have equal average values.

(a) Identify the part of the electromagnetic spectrum used in (i) radar and (ii) eye surgery. Write their frequency range.

(b) Prove that the average energy density of the oscillating electric field is equal to that of the oscillating magnetic field.

How is the speed of em-waves in vacuum determined by the electric and magnetic fields?