58401. The essential condition for antenna array to be linear is that
58402. Directivity gain depends on
58403. The fluctuation in the received signal strength at the receiver of a random variation in the received signal is known as
58404. For an elliptically polarized wave incident on the interface of a dielectric at the Brewster angle the reflected wave will be
58405. The phase velocity in a transmission line is
58406. Which of the antenna is best excited by a waveguide?
58407. An end fire array consisting of several half-wave lengths of directive gain 40, then array length will be
58408. Loop antennas are mostly employed for direction finding (DF) purposes because they are small and hence portable.
58409. The troposphere extends from earth surface to a height of
58410. Antenna reciprocity is put to use in
58411. Which of the following events symbolished the fall the autocracy during the course of French revolution?
58412. For satellite communication, the frequency should be
58413. The velocity of electromagnetic wave in free space is given by
58414. When the phase velocity of an EM wave depends on frequency in any medium, the phenomenon is called
58415. A hertzian dipole has a radiation pattern with
58416. Circular polarized waves result when
58417. Permeance is analogue to
58418. Skip distance (D) is
58419. A very reliable service has to be established between two points on earth separated by 1000 km. The band that will be used as
58420. A rectangular waveguide (2.29 x 1.02) cm operates at a freq. of 11 GHz in TE10 mode. If the maximum potential gradient of the signal is 5 kV/cm, then the maximum power handling capacity of the waveguide will be
58421. A parabolic antenna produces a radiation pattern which is
58422. Considerable ionization occurs between the range
58423. Gain of isotropic antenna is
58424. Antenna is a __________ element
58425. Laplacian of a scalar function v is
58426. The numerical value of directive gain may lie between
58427. The wave propagation occurs without attenuation in case of a
58428. The RSA algorithm uses a ---------cryptography method
58429. A plane EM wave is travelling in an unbound loss less dielectric having μy = 1 and εy = 4, the time average Poynting vector of the wave is 5 W/m3 . The phase velocity vp (assuming velocity of light as 3 x 108 m/sec) is
58430. The phase velocity in a coaxial line is
58431. D-layer extends approximately from
58432. The ionosphere plays a significant role in radio wave propagation at
58433. Radiation resistance for wire antenna is
58434. After reflection from a plane conducting surface, the apparent velocity of electromagnetic wave becomes greater than the velocity of light in free space is called
58435. In a turnstile antenna the crossed dipoles are excited with voltages
58436. Directivity of antenna is defined as
58437. Consider the following; for a loss-less transmission line we can write, Zin = - jz0 for a shorted line with l = λ/8Zin = ± j ∞ for a shorted line with l = λ/4Zin= jz0 for an open line with l = λ/2Zin = 0 for a matched line of any length Select the correct answer using the codes given below codes.
58438. Strip lines are used at
58439. In end fire array the principle direction of radiation
58440. The gain of an half wavelength antenna is
58441. Which of the following does not characterize a ferromagnetic material?
58442. Solution of Laplace equations, which are continuous through the second derivative, are called
58443. The skip distance does not depends upon
58444. Which one of the following statement is correct?
58445. Frequency band used for radar is generally
58446. In case of antenna the lower value of Q indicates
58447. One volt equals
58448. Magnetic susceptibility of a medium is the ratio of
58449. In order to receive a vertically polarized wave, the conductor of the dipole should be mounted
58450. The ----------attack is related to confidentially