HIGHLIGHTED-Microwave-Communications.pdf

A screw b stub c iris d plunger 500 which of the

Info icon This preview shows pages 43–45. Sign up to view the full content.

a. Screw b. Stub c. Iris d. Plunger 500. Which of the following is not a waveguide termination component? a. Tapered pyramid b. Post c. Tapered resistance card d. Stepped resistance card 501. What microwave component can sample part of the power travelling through the waveguide? a. Directional coupler b. Magic tee c. Circulator d. Re-entrant cavity 502. The following are gases used for LASER’s except a. Helium b. Neon c. Argon d. ruby 503. Also known as the optical maser a. Ruby maser b. LASER c. Quantum mechanics d. GaAs maser 504. Paramagnetic means _____________ magnetic a. Almost b. Fully c. Slightly d. Electro 505. Tuning the ruby maser is done by adjusting the _________ to alter the energy level of the ferrous chromium. a. Electric field b. Magnetic field c. Pumping of electrons d. Electromagnetic field 506. To overcome the very narrow bandwidth in ruby maser, _______ is used. a. Magnetron b. TWT c. IMPATT diode d. Gunn diode 507. The following are applications of masers except a. Radioastronomy b. Radiotelescope c. Radar d. ET communications 508. A parametric amplifier is a device which amplifies signal by varying the a. Resistance b. Reactance c. Magnetic field d. Electric field 509. The following are parts of the parametric amplifier except a. Idling circuit b. Pump circuit c. Tuned circuit d. Filter circuit 510. The number of cavities in a magnetron used in practice. a. 4 b. 6 c. 8 d. 10 511. Changing the anode voltage to change the velocity of the electrons in a magnetron tube a. Frequency pushing b. Frequency pulling
Image of page 43

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

c. Strapping d. Pumping 512. The lowest frequency that will propagate through the waveguide while operating in a particular mode. a. Critical frequency b. Cut-off frequency c. MUF d. UHF 513. The mode of a waveguide where there is no component of magnetic field in the direction of propagation a. TE b. TM c. H d. TEM 514. The following are slow wave structures used to retard the RF field in a TWT except a. Helix b. Attenuator c. Waveguide coupled cavity d. NOTA 515. A rectangular waveguide is 5.1 cm by 2.4 cm. The cut-off frequency for the dominant mode is a. 2.94 GHz b. 6.25 GHz c. 664 MHz d. 57.7 GHz 516. Calculate the cut-off wavelength, the guide wavelength and the characteristic impedance of a circular waveguide whose internal diameter is 4 cm for a 10 GHz signal propagated in it in the dominant mode. (kr = 1.84) a. 6.83 cm, 3 cm, 420ῼ b. 3 cm , 6.83 cm, 420 ῼ c. 6.83 cm, 3.34 cm, 420 ῼ d. 6.83 cm, 3.34 cm, 338 ῼ 517. A wave is propagated in a parallel plane waveguide. The frequency is 6 GHz and the plane separation is 3 cm. The cut-off wavelength for the dominant mode, the group and phase velocities are a. 5 cm, 166 Mm/sec,543 Mn/sec b. 6 cm, 166 Mm/sec,543 Mn/sec c. 6 cm, 543 Mm/sec,166 Mn/sec d. 5 cm, 543 Mm/sec,166 Mn/sec 518. If the MTBF of a communication circuit is 20,000 hours and its MTTR is 5 hours, what is its unavailability?
Image of page 44
Image of page 45
This is the end of the preview. Sign up to access the rest of the document.
  • Spring '17
  • Jane Smooth
  • d., microwave

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern