ECE13 Quiz no.1 2nd term SY 2024-2025

When a particular mode is excited in a waveguide, three appears an extra electric component, in the direction of propagation. The resulting mode is

• Transverse-electric

• Transverse-magnetic

• Longitudinal

• Transverse-electromagnetic

As a result of reflections from a plane conducting wall, electromagnetic waves acquire an apparent velocity greater than the velocity of light in space. This is called

(a)  

A signal propagation in a waveguide has a full wave of electric intensity change between the two further walls, and no component of the electric field in the direction of propagation. The mode is

• TE1,1

• TE 1,0

• TM 2,2

• TE 2,0

Indicate which of the following cannot be followed by the word "waveguide".

• Elliptical

• Flexible

• Coaxial

• Ridged

For low attenuation, the best transmission medium is

• Flexible waveguide

• Ridged waveguide

• Rectangular waveguide

• Coaxial line

Why is nitrogen gas sometimes used in waveguide

• To increase the distributed capacitance

• To keep the waveguide dry

• To reduce the skin effect at the walls of the guide

• To raise the guide's wave impedance

The apparent speed of propagation along a waveguide based on the distance between wavefronts along the walls of the guide is called

(a)  

How do you couple in and out of a waveguide?

• Wrap a coil of wire around one end of the waveguide

• Insertion of an E-probe into the waveguide

• Insertion of an H-loop into the waveguide

• Both b and c

Using the TE10 mode, microwave power can only be transmitted in free rectangular guide provided

• The wider dimension is less than one-half of the wavelength in free space

• The narrow dimension is less than one-quarter of the wavelength in free space

• The wide dimension is greater than one-half of the guide wavelength

• The wide dimension is greater than one-half of the wavelength in free space.

If the signal frequency applied to a rectangular guide is increased and the dominant mode is employed

• The free space wavelength is increased

• The phase velocity is increased

• The guide velocity is increased

• The group velocity is increased