For an antenna to be frequency-independent, it should expand or contract in proportion to the impedance
Description : When a dipole antenna of 1/8 length has an equivalent total resistance of 1.5 Watt then the efficiency of the antenna is (A) 0.89159% (B) 8.9159% (C) 89.159% (D) 891.59%
Last Answer : When a dipole antenna of 1/8 length has an equivalent total resistance of 1.5 Watt then the efficiency of the antenna is 89.159%
Description : When an antenna of input resistance 73 ohm is connected to a 50-ohm line and if the losses are ignored then its efficiency will be nearly (A) 0.19 (B) 0.81 (C) 0.97 (D) 1.19
Last Answer : When an antenna of input resistance 73 ohm is connected to a 50-ohm line and if the losses are ignored then its efficiency will be nearly 0.81
Description : Earth coverage dish antenna is used in satellite system. It is characterized by the fact that (a) It is a narrow beam antenna (b) It is Parabolic antenna (c) it is sharply focused within a small area ... the earth (d) it is a wide angle antenna which covers a large area of the surface of the earth
Last Answer : Earth coverage dish antenna is used in satellite system. It is characterized by the fact that it is sharply focused within a small area of the surface of the earth
Description : When it is cold I expand and when it is warm I contract. What am I? -Riddles
Last Answer : Water/ice.
Description : What does it mean for a substance to expand or contract?
Last Answer : Feel Free to Answer
Description : Pipelines in cold countries often burst in winter, because – (1) Water freezes and expands in its volume (2) Temperature of ice is less than that of water (3) Pipelines contract in their volume (4) Pipelines expand due to freezing
Last Answer : (1) Water freezes and expands in its volume Explanation: Water expands on freezing. When liquid water is cooled, it contracts like one would expect until a temperature of approximately 4 degrees ... it expands by approximately 9%. The fact that water expands upon freezing causes icebergs to float.
Description : Water on heating from 1 to 4°C (A) Contracts (B) Expands (C) Has same volume (D) May contract or expand
Last Answer : (A) Contracts
Description : In order to use a substance to make a thermometer the substance must _________ with a temperature change. a. expand b. contract c. change d. increase
Last Answer : change
Description : A stress which develops within an object when it attempts to expand or contract in response to a temperature changes, but cannot, due to being held rigidly in place. a. elongation b. thermal stress c. expansion contraction d. thermal expansion
Last Answer : thermal stress
Description : What happens to etched composite resins after setting: A. Expand B. Contract C. Contract and expand
Last Answer : B. Contract
Description : If water is warmed from 0 degrees Celsius to 6 degrees Celsius, which of the following things happen. Will the water: w) expand steadily x) contract steadily y) expand at first and then contract z) contract first then expand
Last Answer : ANSWER: Z -- CONTRACT FIRST THEN EXPAND
Description : Pipelines in cold countries often burst in winter, because (1) water freezes and expands in its volume (2) temperature of ice is less than that of water (3) pipelines contract in their volume (4) pipelines expand due to freezing
Last Answer : water freezes and expands in its volume
Description : When the current in a power transmission line is increased, the power loss _____________. A. increases as the square of the current B. decreases as the square root of the current C. remains the same, as it is independent of current flow D. increases in direct proportion as the current
Last Answer : Answer: A
Description : The Ku frequency band used in satellite communication (for uplink and downlink) is: (1) 14 GHz and 11 GHz (2) 30 GHz and 20 GHz (3) 70 GHz and 50 GHz (4) 60 GHz and 45 GHz
Last Answer : The Ku frequency band used in satellite communication (for uplink and downlink) is: 14 GHz and 11 GHz
Description : In a PCM system the number of quantization level are 16 and the maximum signal frequency is 4 KHz the transmission bit rate is
Last Answer : In a PCM system the number of quantization level are 16 and the maximum signal frequency is 4 KHz the transmission bit rate is 32 Kbits/sec
Description : The frequency range 30MHz - 300MHz is (A) medium frequency (B) very high frequency (C) super high frequency (D) Infrared frequency
Last Answer : The frequency range 30MHz - 300MHz is very high frequency
Description : In commercial FM broadcasting, the maximum frequency deviation is normally (A) 5 KHz (B) 15 KHz (C) 75 KHz (D) 200 KHz
Last Answer : In commercial FM broadcasting, the maximum frequency deviation is normally 75 KHz
Description : In a radio transmitter, the frequency of the crystal oscillator will be stable for a long time if the quality factor of the crystal resonator is (a) > 100 (b) > 500 (c) > 1000 (d) > 20000
Last Answer : In a radio transmitter, the frequency of the crystal oscillator will be stable for a long time if the quality factor of the crystal resonator is > 1000
Description : A rectangular waveguide is 4.2 cm by 1.85 cm. The cut-off frequency of the dominant mode through this waveguide is (a) 3.57 GHz (b) 3.75 GHz (c) 3.70 MHz (d) 3.57 MHz
Last Answer : A rectangular waveguide is 4.2 cm by 1.85 cm. The cut-off frequency of the dominant mode through this waveguide is 3.57 GHz
Description : The frequency range of FM radio is
Last Answer : The frequency range of FM radio is 88MHz to 108MHz
Description : A tuned circuit has a Q of 100 at its resonant frequency of 500 kHz. Its bandwidth is _____kHz. (A) 50000 (B) 0.2 (C) 600 (D) 5
Last Answer : A tuned circuit has a Q of 100 at its resonant frequency of 500 kHz. Its bandwidth is 5 kHz.
Description : The signal is extended from 96KHz to 100KHz, so the minimum sampling frequency required is (a) 8KHz (b) 200KHz (c) 4KHz (d) 100KHz
Last Answer : 200KHZ
Last Answer : If a wave has frequency of 2 Hz, it has a period of 1/2 s.
Last Answer : In CCIR system B standard, the line frequency 15,625 lines/sec.
Last Answer : The maximum Usable Frequency is dependent on the electron density of the ionospheric layer.
Last Answer : In the telephone, the dial tone has a frequency of 33 Hz.
Description : In a distribution the frequency of a class is replaced with a proportion or percent?
Last Answer : Which one of the two you do does not matter.
Description : 4] In operating a 400hz transformer at 50Hz A. Only voltage is reduced in the same proportion as the frequency B. Only KVA rating is reduced in the same proportion as the frequency C. Both voltage and KVA rating are reduced in the same proportion as frequency D. None of the above
Last Answer : B. Only KVA rating is reduced in the same proportion as the frequency
Description : Increasing the resonant frequency of an end-fed Marconi antenna can be done by A. adding a capacitor in series and reducing the physical length B. adding an inductor in series C. adding an inductor in series D. All of these
Last Answer : A. adding a capacitor in series and reducing the physical length
Description : The effect of adding parasitic elements of a Hertz dipole is to A. make the antenna more omnidirectional B. reduce its resonant frequency C. increase the antenna’s power gain D. All of these
Last Answer : C. increase the antenna’s power gain
Description : When a capacitor is connected in series with a Marconi antenna? A. Antenna open circuit stops transmission B. An inductor of equal value must be added C. No change occurs to antenna D. Antenna resonant frequency increases
Last Answer : D. Antenna resonant frequency increases
Description : What is antenna bandwidth? A. Antenna length divided by the number of elements B. The angle between the half-power radiation points C. The angle formed between two imaginary lines drawn through D. The frequency range over which an antenna can be expected to operate satisfactorily
Last Answer : D. The frequency range over which an antenna can be expected to operate satisfactorily
Description : A Hertz antenna is operating on a frequency of 2182 kHz and consists of a horizontal wire that is hanged between two towers. What is the frequency of its third harmonic? A. 727 kHz B. 6546 kHz C. 436 kHz D. 6.546 kHz
Last Answer : B. 6546 kHz
Description : What is the effect of adding a capacitor in series with an antenna? A. The antenna’s resonant frequency will increase B. The antenna’s resonant frequency will decrease C. The antenna will be physically 5% longer than its electrical length D. A capacitor is never added in series with an antenna
Last Answer : A. The antenna’s resonant frequency will increase
Description : If the length of an antenna is changed from 2.5 meters to 2.8 meters, its resonant frequency will A. increase B. depend on the velocity factor so the resonant frequency can either be increased or decreased C. will be unchanged D. decrease
Last Answer : D. decrease
Description : If the length of a Hertz dipole is decreased A. its resonant frequency will be lowered its distributed inductance will be increased B. its distributed inductance will be decreased C. its ... frequency will be increased D. its distributed capacitance between the antenna and ground will be increased.
Last Answer : C. its resonant frequency will be increased
Description : How is it possible to lower the resonant frequency of Hertz dipole antenna? A. By reducing the frequency at the transmitter B. By connecting a capacitor in series with the antenna C. By the connecting a resistor in series with the antenna D. By connecting an inductor in series with the antenna
Last Answer : D. By connecting an inductor in series with the antenna
Description : The frequency of operation of a dipole antenna cut to a length of 3.4 m. A. 88 MHz B. 44 MHz C. 22 MHz D. 11 MHz
Last Answer : B. 44 MHz
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 : A device that converts high frequency current into electromagnetic wave. A. Antenna B. Loudspeaker C. Microphone D. Transducer
Last Answer : A. Antenna
Description : _________ detects the satellite signal relayed from the feed and converts it to an electric current, amplifies and lower its frequency. A. Horn antenna B. LNA C. Satellite receiver D. Satellite dish
Last Answer : B. LNA
Description : What determines the ability of radar to determine the bearing to a target? A. Speed of light B. Speed of target C. Antenna directivity D. Frequency of signal
Last Answer : C. Antenna directivity
Description : Part of a microwave link can be approximated by free space conditions. The antenna gain are each 40 dB, the frequency is 10 GHz, and the path length is 80 km. Calculate the receive power for a transmitted power of 10 W? A. 0.871 μW B. 871 μW C. 0.871 mW D. 871 nW
Last Answer : A. 0.871 μW
Description : Which frequency reuse method is less effective because of Faraday’s effect? A. Dual polarization B. Reducing antenna beamwidth C. Zonal rotation D. Spin stabilization
Last Answer : A. Dual polarization
Description : How does the gain of a parabolic dish type antenna change when the operating frequency is doubled? A. Gain does not change B. Gain is multiplied by 0.707 C. Gain increases 6 dB D. Gain increases 3 dB
Last Answer : C. Gain increases 6 dB
Description : What type of transmission is radiated from an aircraft’s radio altimeter antenna? A. An amplitude modulated continuous wave B. A pulse position modulated UHF signal C. A differential phase shift keyed UHF signal D. A frequency modulated continuous wave
Last Answer : D. A frequency modulated continuous wave
Description : One of the following prevents a transmitter from emitting a signal that interferes with other stations on frequency during the test. A. Use of low height antenna B. Use of grounded antenna C. Use of dummy antenna D. Use of shielded antenna radiator
Last Answer : C. Use of dummy antenna
Description : It is an average power of a radio transmitter supplied to the antenna transmission line taken during a long sufficient interval of time and compared with the lowest frequency encountered in the modulation ... operating conditions. A. Carrier power B. Rated power C. Mean power D. Peak envelop power
Last Answer : C. Mean power
Description : One of the following is a possible cause of an abrupt frequency variation in a self exited transmitter oscillator circuits resulting to a poor frequency stability to hold a constant frequency ... capacitor in the oscillator D. Loose connections in the oscillator, amplifier, or antenna circuits.
Last Answer : D. Loose connections in the oscillator, amplifier, or antenna circuits.