Consider an air filled rectangular waveguide with a cross-section of $$5\,\,cm\,\, \times \,\,3\,cm$$. For this waveguide, the cut-off frequency (in MHz) of $$T{E_{21}}\,$$ mode is __________________

The modes in a rectangular waveguide are denoted by $$T{E_{mn}}\,$$/$$T{M_{mn}}\,$$ where m and n are the eigen numbers along the larger and smaller dimensions of the waveguide respectively. Which one of the following satements is TRUE?

Which of the following statements is true regarding the fundamental mode of the metallic waveguides shown?

The phase velocity of an electromagnetic wave propagating in a hollow metallic rectangular waveguide in the $$T{E_{10}}$$ mode is