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

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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
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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?
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  • Spring '17
  • Jane Smooth
  • d., microwave

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