Description : When microwave energy is passed through a piece of ferrite in a magnetic field, another effect occurs. If the frequency of the microwave energy is much greater than the electron wobble frequency, the plane of polarization of the wavefront is rotated. This is known as
Last Answer : Faraday Rotation Effect
Description : Why is no emf induced in a rotating coil when it passes through the neutral plane?
Last Answer : No flux lines are cut.
Description : in a directional coupler that is designed to sample the incident energy, what happens to the two portions of the wavefront when they arrive at the pickup probe?
Last Answer : The wavefront portions add.
Description : When a wavefront is radiated into a waveguide, what happens to the portions of the wavefront that do not satisfy the boundary conditions?
Last Answer : Decrease to zero.
Description : A parabolic reflector changes a spherical wavefront to what type of wavefront?
Last Answer : Plane.
Description : What type of lens decelerates a portion of a spherical wavefront
Last Answer : Delay lens
Description : How does a waveguide-type lens focus spherical wavefront microwave energy?
Last Answer : Some wavefronts are accelerated so that all wavefronts exit the lens at the same time
Description : A wavefront undergoes a phase change as it travels along the fiber. If the wavefront transverses the fiber twice and is reflected twice and the total phase change is equal to 1/2 p, will the wavefront disappear? If yes, why?
Last Answer : Yes, the wavefront will disappear because the total amount of phase collected must be an integer multiple of 2 p. (If the propagating wavefronts are out of phase, they will disappear. ... interfere with the wavefronts out of phase. This type of interference is called destructive interference.)
Description : Ferrite devices are useful in microwave applications because they possess what properties?
Last Answer : Magnetic properties and high resistance
Description : If a wave's electric lines of force rotate through 360 degrees with every cycle of rf energy, what is the polarization of this wave?
Last Answer : Circular polarization.
Description : A man is standing near the edge of a uniformly rotating platform about an axis passing through its centre. The speed of rotation of the platform will decrease if he a.extends his arms outwards b.moves ... heavy bag from one of his friends standing near by and holds it in his hand e.107 dynes
Last Answer : d. accepts a heavy bag from one of his friends standing near by and holds it in his hand
Description : A man is standing ner the edge of a uniformly rotating platform about an axis passing through its centre. The speed of rotation of the platorm will decrease if he a.extends his arms outwards b.107 ... towards the axis of rotation d.jumps out from that platform e.take out his coat and throws away
Last Answer : a. extends his arms outwards
Description : On a rainy day, small oil films on water show brilliant colors'. This is due to A. dispersion B. interference C. diffraction D. Polarization 49.The critical angle for a beam of light ... A. absorbed B. totally reflected C. Partially reflected and partially transmitted D. Totally transmitted
Last Answer : C. Partially reflected and partially transmitted
Description : Referred to as a ferrite device that can be used in lieu of a duplexer to isolate a microwave transmitter and receiver when both are connected to the same antenna. A. Isolator B. Circulator C. Coupler D. Diode.
Last Answer : B. Circulator
Description : What is the polarization of the energy radiated by a vertical slot?
Last Answer : Horizontal.
Description : Describe three ways to prevent polarization.
Last Answer : Vent the cell, add a material rich in oxygen, and use a material that will absorb hydrogen.
Description : Describe three ways to prevent polarization
Last Answer : vent the cell, add a material rich in oxygen, and use a material that will absorb hydrogen.
Description : What type of polarization should be used if an antenna is mounted on a moving vehicle at frequencies below 50 megahertz?
Last Answer : Vertical polarization.
Description : What is an advantage of using horizontal polarization at high frequencies?
Last Answer : Less interference is experienced by man-made noise sources
Description : What type of polarization should be used at medium and low frequencies?
Description : The direction of what field is used to designate the polarization of a wave?
Last Answer : Electric (E) field.
Description : Which antenna radiates an omnidirectional pattern in the horizontal plane with vertical polarization? A. Marconi antenna B. Discone antenna C. Horn antenna D. Helical antenna
Last Answer : A. Marconi antenna
Description : A waveguide passive component that brings a smooth change in the direction of axis maintained perpendicular to the plane of polarization? A. L bend B. H bend C. T bend D. X bend
Last Answer : B. H bend
Description : The electric field lies in a plane parallel to the earth’s surface. A. Elliptical polarization B. Horizontal polarization C. Vertical polarization D. Circular polarization
Last Answer : B. Horizontal polarization
Description : The electric field lines in a plane perpendicular to the earth’s surface. A. Elliptical polarization B. Circular polarization C. Horizontal polarization D. Vertical polarization
Last Answer : D. Vertical polarization
Description : Pick up the correct statement from the following: (A) When the electric field oscillates in the direction of the electric vector, a plane polarised wave is formed (B) When the electric vector is ... right angles to the plane of incidence, horizontal polarization wave is formed (D) All of these
Last Answer : Answer: Option D
Description : When a lead is soldered to a pad without passing through the board, it is known as what type of termination?
Last Answer : On-the-board termination.
Description : “Each point on a spherical wavefront may be considered a source of secondary spherical wavefronts”. This is known as the A. Snell’s law B. D’Alembert’s principle C. Appleton’s theory D. Huygen’s principle
Last Answer : D. Huygen’s principle
Description : Zoningis usedwith adielectric antenna inorderto a. reduce the bulk of the lense b. increase the bandwidth of the lens c. increase pin-point focusing d. correct the curvature of the wavefront from a horn that is too short
Last Answer : a. reduce the bulk of the lense
Description : Whose principle or law states that each point on a wavefront may be considered a new wave source? Is it: w) Snell's Law x) Huygen's Principle y) Young's Law z) Hertz's Law.
Last Answer : ANSWER: X -- HUYGEN'S PRINCIPLE
Description : The speed of the rotor is always somewhat less than the speed of the rotating field. What is the difference called?
Last Answer : Slip.
Description : When any plane passing through the central axis of the of the body divides the organism into two identical halves, it is radial symmetry. Which of the
Last Answer : When any plane passing through the central axis of the of the body divides the organism ... ctenophores, echinoderms D. Annelids, arhtropods, housefly
Description : Magnetic Meridian is a – (1) Line parallel to the equator of the Earth (2) Latitude (3) Line joining the geographic north and geographic south of Earth (4) Plane passing through the magnetic north and magnetic south of Earth
Last Answer : (4) Plane passing through the magnetic north and magnetic south of Earth Explanation: Magnetic Meridian is a line on the earth's surface approximating a great circle passing through the north and south ... lines along the surface of the earth. A compass needle is parallel to the magnetic meridian.
Description : 0 Pick up the correct statement from the following: (A) The point through which the resultant of the shear stresses passes is known as shear centre (B) In the standard rolled channels, the shear centre ... horizontal plane and away from the C.G., outside of the leg projection (D) All the above
Last Answer : (D) All the above
Description : Magnetic Meridian is a (1) Line parallel to the equator of the Earth (2) Latitude (3) Line joining the geographic north and geographic south of Earth (4) Plane passing through the magnetic north and magnetic south of Earth
Last Answer : Plane passing through the magnetic north and magnetic south of Earth
Description : Which of the two types of deflection coils (fixed or rotating) is used most often?
Last Answer : Fixed.
Description : What is the purpose of rotating the gimbal assembly in a gyro using a mercury erection system?
Last Answer : Applies torque at the proper point for correct precession.
Description : What is the main advantage of the rotating field alternator?
Last Answer : Output voltage is taken directly from the armature (not through brushes or slip rings).
Description : What determines the number of field poles required to establish a rotating magnetic field in a multiphase motor stator?
Last Answer : The number of phases in the applied voltage.
Description : How can intermodulation interference between two transmitters in close proximity reduced or eliminated? A. Through installing a band-pass filter in the antenna feed line B. Through installing terminated circulator ... high driving power D. By installing a low-pass filter in the antenna feed line
Last Answer : A. Through installing a band-pass filter in the antenna feed line
Description : A plane mirror rotating at an angular velocity of 3 radian/s reflects a light beam. The angular velocity of the reflected beam is -
Last Answer : A plane mirror rotating at an angular velocity of 3 radian/s reflects a light beam. The angular velocity of the reflected beam is -
Description : Assertion A charged particle is rotating in a circular path in uniform magnetic field. Then, plane of circle is perpendicular to the magnetic field. R
Last Answer : Assertion A charged particle is rotating in a circular path in uniform magnetic field. Then, plane of ... . If Assertion is false but Reason is true.
Description : Optically active compounds are capable of (A) Different reactions (B) Rotating plane of polarized light (C) Showing same chemical properties (D) None of these
Last Answer : Answer : B
Description : If an AC generator experiences voltage failure, the cause may be _____________. A. an open in the field circuit B. the brushes shifting out of the neutral plane C. excessive locked-rotor current D. a rotating slip ring
Last Answer : Answer: A
Description : While rotating the theodolite in the horizontal plane, the bubble of the bubble tube takes up the same position in its tube, it indicates (A) The rotation axis is vertical (B) The trunnion ... (C) The line of collimation is perpendicular to vertical axis (D) None of the above
Last Answer : (A) The rotation axis is vertical
Description : When a mass is rotating in a plane about a fixed point, its angular momentum is directed along: (1) the tangent to the orbit (2) a line perpendicular to the plane of rotation (3) the line making an angle of 45° to the plane of rotation (4) the radius
Last Answer : (2) a line perpendicular to the plane of rotation
Description : A direct current passing through a wire coiled around a soft iron core is the description of a simple ____________. A. magnetic shield B. electromagnet C. piezoelectric device D. electromagnetic domain
Last Answer : Answer: B
Description : What is the rotating device that pushes along a ship or aircraft?
Last Answer : It is the propeller.
Description : An electrical device which employs a stationary armature and a rotating electromagnetic field is used aboard ship as a ____________. A. magnetic amplifier B. ship's service alternator C. three-wire DC generator D. saturable core reactor
Description : A coupling is a mechanical device that temporarily joins two rotating shafts to each other. a) True b) False
Last Answer : b) False