In a particular microwave tube an electron beam is traveling with an electromagnetic wave. The arrangement is such that beam of electrons gets accelerated. During this process

A. Waveguide match B. Cavity match C. Direct coax-helix match D. All of the above

A. A long time constant B. Low-pass filters C. The shortest possible time D. The restricted high-frequency response

A. $${\text{S}} = \frac{{2\lambda {\text{R}}}}{{\text{L}}}$$ B. $${\text{S}} = \frac{{3\lambda {\text{R}}}}{{\text{L}}}$$ C. $${\text{S}} = \frac{{\lambda {\text{R}}}}{{\text{L}}}$$ D. $${\text{S}} = \frac{{\text{L}}}{{\lambda {\text{R}}}}$$

A. To focus the beam of primary electrons B. To shield the electron beam from unidirectional magnetic C. As a second anode and to prevent the build-up of secondary field D. All of these