Consider an air-filled rectangular waveguide with dimensions a = 2.286 cm and b = 1.016 cm. The increasing order of the cut-off frequencies for different modes is

An air-filled rectangular waveguide of internal dimension $$a\,\,cm\,\, \times \,\,b\,\,cm$$ (a > b) has a cutoff frequency of 6 GHz for the dominant $$T{E_{10}}$$ mode. For the same waveguide, if the cutoff frequency of the $$T{E_{11}}$$ mode is 15 GHz, the cutoff frequency of the $$T{E_{01}}$$ mode in GHz is _____________

The longitudinal component of the magnetic field inside an air-filled rectangular waveguide made of a perfect electric conductor is given by the following expression $${H_z}(x,\,y,\,z,\,t) = \,0.1\,\cos \,(25\,\,\pi \,x)\,\cos \,(30.3\,\pi y)$$ $$\cos \,(12\,\pi \, \times \,{10^9}\,t\, - \beta \,z)(A/m)$$

The cross-sectional dimemsions of the waveguide are given as a = 0.08 m and b = 0.033 m. The mode of propagation inside the waveguide is

For a rectangular waveguide of internal dimensions $$a\,\, \times \,\,b$$ (a > b), the cut-off frequency for the $$T{E_{11}}$$ mode is the arithmetic mean of the cut-off frequencies for $$T{E_{10}}$$ mode and $$T{E_{20}}$$ mode. If a $$ = \sqrt 5 \,cm$$, the value of b (in cm) is