Objective Questions on Waveguide

Objective Questions on Waveguide

Objective Questions on Waveguide, waveguide questions, and answers, MCQ on waveguides, gate questions on the rectangular waveguides, MCQ on the rectangular and circular waveguides.

Multiple Choice Questions

Q.1. The waves in a waveguide

• travel along the border walls of the waveguide
• are reflected from the side walls but do not travel along them
• travel through the dielectric without touching the walls
• travel along all the four walls

Answer: travel along the border walls of the waveguide

Q.2. Waveguides can carry

• TE mode
• TM mode
• mixed mode
• all

Answer: all

Q.3. The cut-off frequency of a waveguide depends on

• dimensions of the waveguide
• wave mode
• the dielectric property of the medium in the waveguide
• all

Answer: all

Q.4. In Rectangular Waveguide (RWG), the mode subscripts m and n indicate

• no. of half-wave patterns
• no. of full-wave patterns
• no. of the zeros of the field
• none

Answer: no. of half-wave patterns

Q.5. Wave impedance of waveguides in the TE mode can be

• \frac{\eta }{\sqrt{1-(\frac{\lambda }{\lambda _{0}})^{2}}}
• \eta \sqrt{1-(\frac{\lambda }{\lambda _{0}})^{2}}
• both
• none

Answer: \frac{\eta }{\sqrt{1-(\frac{\lambda }{\lambda _{0}})^{2}}}

Q.6. The dominant TE mode in rectangular waveguides is

• TE₀₁
• TE₁₁
• TE₂₀
• TE₁₀

Answer: TE₁₀

Q.7. Cut-off wavelength of rectangular waveguides is

• \frac{2}{\sqrt{(\frac{m}{a})^{2}+(\frac{n}{b})^{2}}}
• \frac{2}{\sqrt{(\frac{m}{a})^{2}-(\frac{n}{b})^{2}}}
• both
• none

Answer: \frac{2}{\sqrt{(\frac{m}{a})^{2}+(\frac{n}{b})^{2}}}

Q.8. In RWG, for dominant mode, the cut-off wavelength is

• 2a
• 2b
• a
• none

Answer: 2a

Q.9. An air-filled rectangular waveguide has dimensions of 6 × 4 cm. Its cut-off frequency for the TE10 mode is

• 2.5 GHz
• 25 GHz
• 25 MHz
• 5 GHz

Answer: 2.5 GHz

Q.10. In hollow rectangular waveguides,

• the phase velocity is greater than the group velocity
• the phase velocity is greater than the velocity of light in free space
• both
• none

Answer: both

Q.11. The dominant mode in the circular waveguide is

• TE₁₀
• TE₁₁
• TE₀₁
• TE₁₂

Answer: TE₁₁

Q.12. Nonexistent modes in circular waveguides are

• TE₁₀
• TE₀₀
• both
• none

Answer: TE₀₀

Q.13. Degenerate modes in circular waveguides are

• TE₀₁ and TM₁₁
• TE₂₂ and TM₂₂
• both
• none

Answer: TE₀₁ and TM₁₁

Q.14. Theoretically, the number of modes that can exist in cylindrical waveguides are

• zero
• one
• two
• infinite

Answer: infinite

15. Guided wavelength of cylindrical waveguides is

• \frac{\lambda}{\sqrt{1-(\frac{\lambda}{\lambda _{0}})^{2}}}
• \frac{\lambda}{\sqrt{1-(\frac{f_{0}}{f})^{2}}}
• both
• none

Answer: both