Q. Calculate the directivity of a given linear end fire, uniform array of 20 element, each separated by λ/3

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Q. For a 400 kHz transmission line having L = 0.5 mH/km, C = 0.08 mF and negligible R and G, the velocity propagation will be

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Q. Antenna efficiency of antenna is, if radiation resistance is 370 Ω and loss resistance is 100 Ω

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Q. At a particular time it is observed that the frequencies of F layer at Delhi is 3 MHz the maximum electron density is

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Q. The effective length of an λ/2 antenna (Given Rr = 73 Ω and (Ae)max = 0.13 λ² and η = 120 π is __________ .

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Q. A vertical wire of 1 meter length carries a current of 1 A at 10 MHz. The total radiated power is nearly

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Q. The length of half-wave antenna is at 30 MHz

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Q. For a 400 kHz transmission line having L = 0.5 mH/km, C = 0.08 mF and negligible R and G, the characteristic impedance will be

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Q. Beamwidth (between first nulls) will be for an antenna at 3 MHz with directivity of 100

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Q. A broadside array consisting of 200 cm wavelength with 10 half-wave dipole spacing 10 cm. And if each array element feeding with 1 amp. current and operating at same frequency then find the radiated power

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Q. If wave of critical frequency 30 MHz is departing at an angle of 60°, then the MUF is given to be

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Q. An antenna having an effective temperature of 27°K is fed into a microwave amplifier that has an effective noise temperature of 30 K. Calculate the available noise power per unit bandwidth

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Q. Calculate cut off frequency for dominant mode in rectangular waveguide if dimensions are a = 2, b = 1 cm.

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Q. The input impedance for a half dipole if radii of both the antenna is 4 and 8 meter respectively

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Q. A rectangular waveguide measures 3 x 4.5 cm internally and has a 10 GHz signal propagated in it. Calculate the guide wavelength for dominant mode.

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Q. A rectangular waveguide measures 3 x 4.5 cm internally and has a 10 GHz signal propagated in it. Calculate the cut off frequency for dominant mode.

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Q. An isolated sphere in air has a radius equal to 1/4πε₀ meter, its capacitance is

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Q. Find cut off wavelength for mode TE11 in a circular waveguide having radius 2 cm. Assume K'a = 1.841

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Q. The refractive index of E layer, if angle of incidence is 30°

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Q. A transmission line having 50 Ω impedance is terminated in a load of (40 + j 30) Ω. The VSWR is

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