Q. A broadside array operating at 100 cm wavelength consist of 4 half-wave dipoles spaced 50 cm apart. Each element carries radio frequency current in the same phase and of magnitude 0.5 A. The radiated power will be

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Q. A wave is propagated in a waveguide at frequency of 9 GHz and separation is 2 cm between walls Calculate group velocity for dominant mode.

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Q. For F1 layer the maximum ionic density is 2.3 x 10⁴ electrons per cc. The critical frequency for this layer will be

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Q. The velocity of electromagnetic wave in a good conductor is

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Q. Radiation intensity of a dipole depends strongly on frequency. If at a frequency f, the intensity of radiation is 'I'. Then at a frequency of f/2, the intensity will be

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Q. A material has conductivity of 10¯² mho/m and a relative permittivity of 4. The frequency at which conduction current in the medium is equal to displacement current is

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Q. A transmission line is feeding 1 watt of power to a horn antenna having a gain of 10 dB. The antenna is matched to the transmission line. The total power radiated by the horn antenna into the free space is

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Q. An end fire array consisting of several half-wave lengths of directive gain 40, then find the width of major lobe

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Q. A uniform plane EM wave incident normally on a plane surface of a dielectric material is reflected with a VSWR of 3. What percentage of incident power that is reflected?

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Q. Poynting vector is associated with which of the following?

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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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