58251. The maximum effective aperture of an antenna which is operating at wavelength of 2 m and has directivity of 100 is
58252. The waveguides compared to equivalent transmission lines at low frequency are
58253. The current distribution of a half wave dipole is
58254. In case of static electric field Maxwell's divergence equation states that:
58255. For a reflection co-efficient of 0.5, the value of SWR is
58256. A rectangular waveguide having TE10 mode as dominant mode is having a cut off frequency of 18 GHz for the TE30 mode. The inner broad wall dimension of the rectangular waveguide is
58257. A 50 p characteristic impedance line is connected to a load which shows a reflection coefficients of 0.268. If Vin = 15 volt, then the net power delivered to the load will be
58258. 1 dB is equal to __________ nepier
58259. Cassergain feed is used with a parabolic reflector to
58260. Voltage standing wave pattern in a loss less transmission line with characteristic impedance 50 Ω and a resistive load is shown in the figure.
The value of load resistance is
58261. For the same length of arrays, half power beam-width of binomial array
58262. The effective electrical length of an antenna is __________ its physical length
58263. The direction in a Yagi Uda antenna is longer than the radiating element.
58264. The intrinsic impedance of free space
58265. To couple a coaxial line to a parallel to wire line it is best to use a
58266. The shunt admittance of a transmission line is given by
58267. A dipole antenna was radiating with some excitation in free space radiating a certain amount of the power. If this antenna is immersed in a lake where water is non-dissipative but has a dielectric constant of 81, the radiated power with the same excitation will
58268. If short-circuited and open circuited impedances are 5 ohms and 20 ohms, then characteristic impedance is
58269. Electric lines of force do not cross each other because
58270. A person with a receiver is 5 km away from the transmitter. What is the distance that this person must move further to detect at 3 dB decrease in signal strength?
58271. For free space propagation
58272. SHF range is
58273. In figure the voltage distribution on a vertical earthed antenna is represented by
58274. The direction in a Yagi Uda antenna
58275. In cell phone antennas are
58276. Antenna commonly used for microwave links are
58277. For a good conducting medium the intrinsic impedance is
58278. For an ideal antenna, numerical value of directivity must be
58279. The force in a magnetic field is given by F = qvB
58280. An electromagnetic wave is incident normally on a dielectric boundary. It is
58281. According to maximum power transfer theorem, if the load is inductive, the source should be
58282. According to Siegel and Labus, antenna can be treated as
58283. Given figure shows a 90° sector of spherical reflector with vertex 'V', centre of curvature 'C' and equal distances VD, DF, FE and EC. When a beam of EM wave is incident parallel to the axis, all the energy will pass through the region
58284. The value of susceptibility in case of vacuum is taken as
58285. Self impedance is
58286. Equipotential surfaces about a point charge are in which one of the following forms?
58287. __________ will have the least value of relative permeability.
58288. The relative permeability is taken as unity for which of the following?
58289. The disturbance from adjacent power lines is known as
58290. Magnesium is alloyed with conducting materials for antenna primarily with the purpose of
58291. Which of the following term applies to troposcatter propagation?
58292. The effective refraction index of the ionosphere for radio wave is
58293. For space propagation, what will be the electric field strength at receiving antenna
58294. A medium is said to be isotropic when
58295. The radiation resistance of a resonant long wire antenna of half wavelength (λ/2) is given
58296. A uniform wave have components
58297. The measure of mismatch between the load and the transmission line is known as
58298. Ionospheric storm causes an abnormal decrease in the critical frequency.