Description : An accurate clock shows 9 o’clock in the morning. Through how many degrees will the hour hand rotate when the clock shows 2 o’clock in the afternoon? a) 120 b) 150 c) 180 d) 360
Last Answer : Answer Key : b
Description : What is meant by referring to electromagnetic waves as having circular polarization? A. The electric field is bent into a circular shape. B. The electric field rotates C. The electromagnetic wave continues to circle the earth D. The electromagnetic wave has been generated by a quad antenna
Last Answer : B. The electric field rotates
Description : Type of emission produced by one of the early radio transmitter in trains of damped RF ac waves where its oscillator is coupled to a long wire antenna, normally used in radio telegraph and having sidebands on its carrier. A. Digital emission B. Key emission C. Cycle emission D. Spark emission
Last Answer : D. Spark emission
Description : The direction of what field is used to designate the polarization of a wave?
Last Answer : Electric (E) field.
Description : iv) A rectangular coil free to rotate is placed in uniform magnetic field with its plane parallel to the magnetic lines of force. Then the coil willa) rotate to maximize the magnetic flux through ... since the magnetic flux through its plane is zero.d) experience the constant torque equal to NBIA
Last Answer : iv) A rectangular coil free to rotate is placed in uniform magnetic field with its plane parallel ... d) experience the constant torque equal to NBIA
Description : What determines antenna polarization? A. The frequency of the radiated wave B. The direction of the radiated wave C. The direction of the magnetic field vector D. The direction of the electric field vector
Last Answer : D. The direction of the electric field vector
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 : 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 : The Doppler effect causes a change in what aspect of rf energy that strikes a moving object?
Last Answer : Frequency.
Description : Atmospheric interference with the travel of electromagnetic energy increases with what rf energy characteristic?
Description : An accurate clock shows 8 o'clock in the morning. Through how may degrees will the hour hand rotate when the clock shows 2 o'clock in the afternoon?
Last Answer : 240
Description : Rotating the plane of polarization of a wavefront by passing it through a ferrite device is called what?
Last Answer : . Faraday rotation.
Description : What is the polarization of the energy radiated by a vertical slot?
Last Answer : Horizontal.
Description : which waveforms on the left have a resultant wave of zero, and what is indicated by these waves?
Last Answer : 2 and 6 have zero resultant wave and they indicate that the incident and reflected waves are 180 degrees out of phase at all parts.
Description : The mode theory uses electromagnetic wave behavior to describe the propagation of the light along the fiber. What is a set of guided electromagnetic waves called?
Last Answer : Modes of the fiber.
Description : What two methods are used to compensate for the problems that cause low gain in an rf amplifier?
Last Answer : . RF transformers are used and the transistor is neutralized.
Description : What problem is caused in an rf amplifier by a loosely coupled transformer?
Last Answer : A too-narrow bandpass.
Description : What is the most common form of coupling for an rf amplifier?
Last Answer : Transformer coupling.
Description : Can a parallel LC circuit be used as the frequency determining network for an rf amplifier?
Last Answer : Yes.
Description : What is the purpose of a frequency-determining network in an rf amplifier?
Last Answer : To provide maximum impedance at the desired frequency.
Description : If current gain is required from an rf amplifier, what type of component should be used as an output coupling element?
Last Answer : A step-down transformer.
Description : What is the result of pulsing a pulsed rf amplifier when no rf is present?
Last Answer : Oscillations at an undesired frequency.
Description : Rotation of an rf-feed source to produce a conical scan pattern is identified by what term?
Last Answer : Nutation.
Description : At what point on an open-circuited rf line do voltage peaks occur?
Last Answer : At 1/2 wavelength from the end and at every 1/2 wavelength along the line
Description : If the rf amplifier discussed has an 80 milliwatt input, what would be the maximum output?
Last Answer : 800 watts.
Description : What is the most common method of testing a fixed rf attenuator?
Last Answer : Rf substitution method.
Description : Normally, how are high-power rf tubes tested?
Last Answer : In their circuit.
Description : Name the three main sections of a typical rf signal generator.
Last Answer : Oscillator circuit, modulator, and output control circuit.
Description : How does the reactance-tube modulator impress intelligence onto an rf carrier?
Last Answer : By changing the reactance of an oscillator circuit in consonance with the modulating voltage.
Description : For what class of operation is the final rf power amplifier of a plate-modulator circuit biased?
Last Answer : Class C
Description : Longitudinal waves do not exhibit a. Polarization b. Refraction c. Reflection d. Diffraction
Last Answer : a. Polarization
Description : What is caused by the transverse nature of electromagnetic waves? A. Polarization B. Interference C. Beamwidth D. Gain
Last Answer : A. Polarization
Description : Longitudinal waves do not exhibit ∙ a. Polarization ∙ b. Refraction ∙ c. Reflection ∙ d. Diffraction
Description : The absorption ofradiowaves bythe atmosphere depends on a. their frequency b. their distance from the transmitter c. the polarization of the waves d. the polarization of the atmosphere
Last Answer : a. their frequency
Description : .In electromagneticwaves,polarization a. is caused by reflection b.isdue to the transversenature ofthewaves c. results from the longitudinal nature of the waves d. is always vertical in an isotropic medium
Last Answer : b.isdue to the transversenature ofthewaves
Description : what- The Ferris wheel has forty spokes. The center of rotation is the vertex of each triangle.How many degrees does the Ferris wheel rotate from one gondola to the next?
Last Answer : 9 degrees
Description : If the spider rotates 144 degrees at each step how many degrees does she rotate to create the star?
Last Answer : What is the answer ?
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 : In a dc motor that must be able to rotate in both directions, how is the direction changed?
Last Answer : By reversing either field or armature connections
Description : To measure incident power, you must rotate the coupler detector of the wattmeter so that the arrow indicating power flow points toward which end of the transmission line?
Last Answer : Load.
Description : RF Design Question: 40MHz to 10MHz sine wave?
Last Answer : Is the 40 MHz manufacturered digitally? Do you have access to the clock/driver oscillator? Is everything analog? Can you add a 30 MHz signal and filter out the resulting 10 and 70 Mhz beats? You can synthesize a 10 MHz yourself with either a 555 timer or a Statek chip.
Description : Which of the following parts of the radio receiver represent the component that extracts the desire RF signal from the electromagnetic wave? A. AF amplifier B. Antenna C. Detector D. Crystal
Last Answer : B. Antenna
Description : Which of the following methods cannot be used to increase the bandwidth for cascaded RF amplifier stages? A) Wave traps in each stage B) Stagger tuning C) A shunt damping resistor across each tuned circuit D) Doubled tuned transformers with tighter coupling
Last Answer : A) Wave traps in each stage
Description : What is the meaning of forward power? A. The power traveling from the transmitter to the antenna. B. The power radiated from the top of an antenna system. C. The power produced during the positive half of an RF cycle. D. The power used to drive a linear amplifier.
Last Answer : A. The power traveling from the transmitter to the antenna.
Description : What is the period of a wave? A. The number of degrees in tone cycle B. The number of zero crossing in one cycle C. The amplitude of the wave D. The time required to complete one cycle
Last Answer : D. The time required to complete one cycle
Description : If a modulating wave is sampled 10 times per cycle with a 5-element binary code, how many bits of information are required to transmit the signal?
Last Answer : 28. 50.