Description : What is the impedance of a balance 4-wire with a diameter of 0.25 cm and spaced 2.5 cm apart using an insulator with a dielectric constant of 2.56? A. 100Ω B. 65Ω C. 75 Ω D. 50 Ω
Last Answer : A. 100Ω
Description : When speaking of antennas. ______ is a section which would be a complete antenna by itself. A. image B. top loading C. bay D. quarterwave
Last Answer : C. bay
Description : Most mobile satellite array uses ___________ in transforming 50 to 150 Ω impedance. A. stub B. balun C. quarter-wavelength transformer D. microstrip tapers.
Last Answer : C. quarter-wavelength transformer
Description : What is the impedance in ohms of a transformer marked for 25V, 4W, when the secondary is correctly loaded? A. 150 Ω B. 156 Ω C. 160 Ω D. 165 Ω
Last Answer : B. 156 Ω
Description : A receiver connected to an antenna whose resistance is 50 Ω has an equivalent noise resistance of 30Ω. Calculate its equivalent noise temperature if the noise figure is equal to 1.6. A. 17.4 K B. 174K C. 1.74K D. 17K
Last Answer : B. 174K
Description : What is the input impedance of a transmission line if its characteristic impedance is 300 Ω and the load is 600 Ω? Assume a quarter wavelength section only. A. 150 kΩ B. 150 mΩ C. 150 Ω D. 2 Ω
Last Answer : C. 150 Ω
Description : Determine the standing wave ratio of a 300-Ω line whose load is 400+j150 Ω. A. 3.55 B. 1.67 C. 5.53 D. 3.35
Last Answer : B. 1.67
Description : A transmitted signal 5 meters in wavelength is received by an antenna coil having a 50-Ω resistance and a 0.01 H inductance. What is the capacitance of the tuner shunting the antenna coil at this point? A. 0.704 fF B. 0.704 μF C. 0.704 nF D. 0.704 mF
Last Answer : A. 0.704 fF
Description : The input terminal impedance at the center of a folded dipole antenna is A. 72 Ω B. 300 Ω C. 50 Ω D. 73 Ω
Last Answer : B. 300 Ω
Description : In the given figure, AB is the diameter where AP = 12 cm and PB = 16 cm. If the value of π is taken 3, what is the perimeter of the shaded region? (a) 58 cm (b) 116 cm (c) 29 cm (d) 156 cm
Last Answer : (a) 58 cm
Description : .Total how many students in the college know all three languages? (1)108 (2)132 (3)169 (4)137 (5)142
Last Answer : (3)169
Description : The front-end of a television receiver, having a bandwidth of 7Mhz, and operating at a temperature of 27˚C , consists of an amplifier having a gain of 15 followed by a mixer whose gain is 20. The ... equivalent noise resistance for this television receiver. A. 8760 Ω B. 875Ω C. 8.76Ω D. 0.876Ω
Last Answer : B. 875Ω
Description : Transmission lines when connected to antenna have A. capacitive load B. resistive load whose resistance is less than characteristics impedance C. resistive load at the resonant frequency D. resistive load whose resistance is greater than the characteristic impedance of the line
Last Answer : C. resistive load at the resonant frequency
Description : What is the effective radiated power of a repeater with 75 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 6 dB antenna gain? A. 37.6 W B. 237 W C. 150 W D. 23.7 W
Last Answer : A. 37.6 W
Description : 129 McCullum scored ______ on 58 balls in T20 cricket and set a world record of highest runs by any individual against Bangladesh at Pallekele on 21 September 2012. A. 116 B. 120 C. 123 D. 137
Last Answer : ANSWER: C
Description : McCullum scored ______ on 58 balls in T20 cricket and set a world record of highest runs by any individual against Bangladesh at Pallekele on 21 September 2012. 120 A. 116 B. 120 C. 123 D. 137
Description : McCullum scored ______ on 58 balls in T20 cricket and set a world record of highest runs by any individual against Bangladesh at Pallekele on 21 September 2012. A. 116 B. 120 110 C. 123 D. 137
Description : New Zealand Cricket McCullum scored ______ on 58 balls in T20 cricket and set a world record of highest runs by any individual against Bangladesh at Pallekele on 21 September 2012. A. 116 B. 120 C. 123 D. 137
Description : What is the effective radiated power of a repeater with 75 watts transmitter power output, 4 dB feedline loss, 3 dB duplexer and circulator loss, and 10 dB antenna gain? A. 600 W B. 75 W C. 18.75 W D. 150 W
Last Answer : D. 150 W
Description : An antenna has a radiation resistance of 72 Ω a loss resistance of 8 Ω and a power gain of 16. Find efficiency and directivity.
Last Answer : An antenna has a radiation resistance of 72 Ω a loss resistance of 8 Ω and a power gain of 16. Find efficiency and directivity.
Description : A transmission line of unknown impedance is terminated with two different resistances, and an SWR is measured each time. With a 75 Ω termination, the SWR measures 1.5. With a 300 Ω termination, it measures 2.67. What is the impedance of the line? A. 100 Ω B. 212 Ω C. 300 Ω D. 112 Ω
Last Answer : D. 112 Ω
Description : Calculate critical damping coefficient in N/m/s from the following data: mass = 100Kg ω = 40rad/s a) 25,132 b) 26,132 c) 27,132 d) 28,132
Last Answer : a) 25,132
Description : Calculate critical damping coefficient in Ns/m from the following data. mass = 200Kg ω = 20rad/sa) 25,132 b) 26,132 c) 27,132 d) Not possible
Last Answer : d) Not possible
Description : A ground station is operating to a geostationary satellite at a 5° angle of elevation. Calculate the round-trip time between ground station and satellite. A. 275 s B. 275 ms C. 137.5 s D. 137.5 ms
Last Answer : B. 275 ms
Description : Determine the conductance of a two-wire open line with the following parameters: D = 4 in., d = 0.1 in. and ρ = 2.6x108 Ω-m. A. 2.76x10-9 S/m B. 2.76x10-6 S/m C. 2.76x10-12 S/m D. 2.76x10-3 S/m
Last Answer : A. 2.76x10-9 S/m
Description : What is actual length in feet of a one-half wavelength of a coax with a velocity factor of 0.59 at 26 MHz? A. 11.16 B. 40.29 C. 42.46 D. 46.28
Last Answer : A. 11.16
Description : McCullum scored ______ on 58 balls in T20 cricket and set a world record against Bangladesh at Pallekele on 21 September 2012. A. 187 B. 123 C. 152 D. 132
Last Answer : ANSWER: B
Description : An isotropic radiator is A. in the northern hemisphere B. an antenna high enough in the air C. an antenna whose directive pattern is substantially incredible D. a hypothetical, omnidirectional antenna
Last Answer : D. a hypothetical, omnidirectional antenna
Description : Calculate the noise figure of the receiver whose RF amplifier has an input resistance of 1000Ω and an equivalent shot-noise resistance of 2000Ω, a gain of 25 and load resistance of 125 kΩ. Given that the bandwidth is 1. ... to an antenna with an impedance of 75Ω. A. 30.3 B. 3.03 C. 303 D. .303
Last Answer : A. 30.3
Description : Determine the effective radiated power of 20 kW TV broadcast transmitter whose antenna has a field gain of 2. A. 40 kW B. 80,000 watts C. 40,000 watts D. 8,000 watts
Last Answer : B. 80,000 watts
Description : ECE Board Exam March 1996 A receiver connected to an antenna whose resistance is 50 ohms has an equivalent noise resistance of 30 ohms. What is the receiver’s noise temperature? A. 754 K B. 464 K C. 174 K D. 293 K
Last Answer : C. 174 K
Description : What is the gain, in dB of a helical antenna with diameter of λ/3, 10 turns at pitch of λ/4, used at 100 MHz? A. 16 B. 41.1 C. 31.4 D. 1.25
Last Answer : A. 16
Description : The standard ASCII A. is version II of ASC B. is used only in US and Canada C. has 132 characters including 32 control characters D. is subset of 8-bit EBCDIC code
Last Answer : C. has 132 characters including 32 control characters
Description : ___________ is device that measures the internal open circuit voltage of an equivalent noise generator having an impedance of 600Ω and delivering noise power to a 600 Ω load. A. Psophometer B. Barometer C. Reflectometer D. Voltmeter
Last Answer : A. Psophometer
Description : The first stage of a two-stage amplifier has a voltage gain of 10, a 600 Ω input resistor, a 1600Ω equivalent noise resistance and 27kΩ output resistor. For the second stage, these values are 25, 81kΩ, 19kΩ, and 1MΩ, ... this two stage amplifier. A. 2,518 kΩ B. 2,518 Ω C. 251.8 Ω D. 12,518 Ω
Last Answer : B. 2,518 Ω
Description : What is the end impedance of a half-wave dipole? A. 73 Ω B. 72 Ω C. 250 Ω D. 2500 Ω
Last Answer : D. 2500 Ω
Description : What is the characteristic impedance of a single wire with a diameter d= 0.25 mm placed at the center between grounded parallel planes separated by 1 mm apart. The wire is held by a material with a velocity factor of 0.75. A. 85 Ω B. 63 Ω C. 50 Ω D. 75 Ω
Last Answer : D. 75 Ω
Description : Two resistance 100Ω ± 5Ω ± 15Ω are connected in series. If the errors are specified as standard deviations, the resultant error will be
Last Answer : Two resistance 100Ω ± 5Ω ± 15Ω are connected in series. If the errors are specified as standard deviations, the resultant error will be ± 15.8Ω
Description : Factors that determine the radiation resistance of an antenna A. Transmission line length and height of antenna B. The location of the antenna with respect to nearby objects C. It is a constant for all antennas since it is physical D. Sunspot activity and the time of day
Last Answer : B. The location of the antenna with respect to nearby objects
Description : If a transmission line has a power loss of 6 dB per 100 feet, what is the power at the feed point to the antenna at the end of a 200 foot transmission line fed by a 100 watt transmitter? A. 70 watts B. 50 watts C. 25 watts D. 6 watts
Last Answer : D. 6 watts
Description : What is included in the total resistance of an antenna system? A. Radiation resistance plus space impedance B. Radiation resistance plus transmission resistance C. Transmission line resistance plus radiation resistance D. Radiation resistance plus ohmic resistance
Last Answer : D. Radiation resistance plus ohmic resistance
Description : What is the maximum line-of-sight distance between a paging antenna 250 ft high and a pager receiver 3.5ft of the ground? A. 25 km B.25mi C. 70.73 km D. 70.73 mi
Last Answer : B.25mi
Description : Determine the dB gain of a receiving antenna which delivers a microvolt signal to a transmission line over that of an antenna that delivers a 20 microvolt signal under identical circumstances. A. 10 dB B. 6 dB C. 3 dB D. 8 dB
Last Answer : B. 6 dB
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 : What is meant by the term radiation resistance for an antenna? A. The resistance in the trap coils to received signal B. An equivalent resistance that would dissipate the same amount of power as ... antenna C. The specific impedance of the antenna D. Losses in the antenna elements and feed line
Last Answer : B. An equivalent resistance that would dissipate the same amount of power as that radiated from an antenna
Description : Refers to a type of beam antenna which uses two or more straight elements arranged in line with each other. A. Dipole antenna B. Yagi antenna C. Whip antenna D. Rhombic antenna
Last Answer : B. Yagi antenna
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 : What is a driven element of an antenna? A. Always the rearmost element B. Always the forwardmost element C. The element fed by the transmission line D. The element connected to the rotator
Last Answer : C. The element fed by the transmission line
Description : Referred to as an average power from the radio transmitter supplied to the antenna transmission line taken during one radio frequency cycle under no modulation. A. Carrier power B. Rated power C. Peak envelop power D. Mean power
Last Answer : A. Carrier power