Question

In this mode, the electric field is purely transverse to the direction of propagation, whereas the magnetic field is not. Name the mode of propagation of microwaves.
1. Transverse Electromagnetic Waves
2. Transverse Electric Waves
3. Transverse Magnetic Waves
4. Hybrid Waves

Answer 1

Correct Answer - Option 2 : Transverse Electric Waves

Explanation:-

Waveguide: A hollow metallic structure for propagation of electromagnetic waves from one end to another by successive reflection from inner walls.

Modes: Transverse and longitudinal arrangement of electric and magnetic fields gives rise to unique configurations in space called modes.

Modes of propagation: Depending upon the orientation and spreading of the Electric field and magnetic field different modes that exist are discussed below.

By default, we will consider Z as the direction of wave propagation.

Transverse Electric Wave (TE): The electric field is purely transverse to the direction of propagation but the magnetic field is not.

E_Z = 0 & H_Z ≠ 0

Transverse Magnetic Wave (TM): The magnetic field is purely transverse to the direction of propagation while the electric field is not.

E_Z ≠ 0 & H_Z = 0

Transverse Electromagnetic Wave (TEM): There is no component of either Electric field or magnetic field in the Z direction. This means the electric field and magnetic field are transverse to the direction of the wave propagation.

E_Z = 0 & H_Z = 0

Hybrid Wave: In this type of mode neither the electric field nor the magnetic field is purely transverse to the direction of propagation.

E_Z ≠ 0 & H_Z ≠ 0

MODE	Electric Component	Magnetic Component
TEM	EZ = 0	HZ = 0
TE	EZ = 0	HZ ≠ 0
TM	EZ ≠ 0	HZ = 0
Hybrid	EZ ≠ 0	HZ ≠ 0

From the above discussion, it is clear that the mode of propagation is the Transverse Electric wave.

• TEM mode does not exist in rectangular waveguide, it can exist only in a two-conductor system.
• TEM modes need to be considered at low frequencies.