Description : You are measuring a voice channel at a -4 dB test point level, the meter reads -73 dBm (pure test tone) convert the reading in dBmCO. A. 16 B. 18 C. 22 D. 12
Last Answer : C. 22
Description : At what power level does a 1 KHz tone cause zero interference (144 weighted)? A. 90 dB B. 90 dBm C. -90 dBm D. -90 dBm
Last Answer : D. -90 dBm
Description : ECE Board Exam March 1996 At what power level does a 1 kHz tone cause zero interference (144 weighted) ? A. -90 dB B. -90 dBm C. 90 dBm D. 90 dB
Last Answer : B. -90 dBm
Description : ECE Board Exam March 1996 The power of standard test tone is normally ____________. A. 1 dB B. 0 mW C. 1 mW D. 1 W
Last Answer : C. 1 mW
Description : Your Western Electric 3A test set meter reading is -23 dBm at at test point level of -8 dB. This is ______ dBrnc0. A. 75 B. 29 C. 30 D. 31
Last Answer : A. 75
Description : You are measuring noise in a voice channel at 7 dB test point level. The meter reads -56 dBm (FIA weighted). What is the reading in dBrnc? A. 20 B. 32 C. 35 D. 25
Last Answer : C. 35
Description : In measuring noise in a voice channel at a 4 dB test point level, the meter reads -70 dBm (F1A weighted), convert the reading to pWp. A. 53 B. 93 C. 63 D. 83
Last Answer : B. 93
Description : You are measuring noise at a -6 dB level point, using the Lenkurt 601A, F1A weighting network, and a flat meter. The meter reading is -59 dBm. This is _________ dBa0. A. 24 B. 12 C. 23 D. 32
Last Answer : D. 32
Description : A reading of -50 dBm on the disturbing pair, and -80 on the disturbed pair equals _____ dB of crosstalk coupling. A. 20 B. 30 C. 60 D. 25
Last Answer : B. 30
Description : Interfering effect of noise, C message weighted, is _________. A. dBa B. dBm C. dBmc D. dB
Last Answer : C. dBmc
Description : Which stands for dB relative level? A. dBrn B. dBm C. dBr D. dBa
Last Answer : C. dBr
Description : What is the reference tone level for dBa? A. -90 dBm B. -82 dBm C. -67 dBm D. -85 dBm
Last Answer : D. -85 dBm
Description : What is the reference tone level for dBrn? A. -90 dBm B. -82 dBm C. -67 dBm D. -85 dBm
Last Answer : A. -90 dBm
Description : Reference noise is ___________. A. a 1000 Hz, -90 dBm tone B. a noise that creates the same interfering effect as a 1000Hz, -90dBm tone C. a noise that creates zero dBrn in a voice channel D. B and C above
Last Answer : D. B and C above
Description : ECE Board Exam March 1996 What is the reference tone level for dBm? A. -82 dBm B. -85 dBm C. -67 dBm D. -90 dBm
Description : ECE Board Exam March 1996 Crosstalk coupling is ___________. A. dBm (disturbing pair) minus dBm (disturbed pair) B. the difference between readings on a cable pair with a tone and a cable pair without ... a cable C. signals from one circuit that get into another circuit D. All of these are true
Last Answer : D. All of these are true
Description : What is the standard test tone used for audio measurements? A. 100 Hz B. 500 Hz C. 1000 Hz D. 2000 Hz
Last Answer : C. 1000 Hz
Description : What is the reference noise level? A. 10 pW B. 0 dBm C. 1mW D. -90 dBm
Description : The standard deviation of the variation in the transmission loss of a circuit should not exceed A. 3 dB B. 1 dB C. 5 dB D. 0.5dB
Last Answer : B. 1 dB
Description : In reference to dB meters, 0 dBm represents 1 milliwatt into what value of load?
Last Answer : 600-ohm load.
Description : For a single mode optical cable with 0.25 dB/km loss, determine the optical power 100 km from a 0.1-mW light source. ∙ A. -45 dBm ∙ B. -15 dBm ∙ C. -35 dBm
Last Answer : ∙ C. -35 dBm
Description : What is the equivalent output of a circuit in dBm, if it is has an output of 10 watts? A. 10 dBm B. 30 dBm C. 20 dBm D. 40 dBm
Last Answer : D. 40 dBm
Description : What is the noise factor if the equivalent noise temperature is 25 K? A. 1.09 B. 0.09 C. 0.36 dBm D. 0.36
Last Answer : A. 1.09
Description : The agreed standard for measuring loudness is the loudness sensation produced by a 1000 Hz sine wave _____ dB above the listener’s threshold of hearing. A. 80 B. 50 C. 30 D. 40
Last Answer : D. 40
Description : Refers to a continuous tone generated in a local exchange terminal through a combination of two frequencies 350 Hz, and 440 Hz. A. Busy tone B. Call waiting tone C. Dial tone D. Standard tone
Last Answer : B. Call waiting tone
Description : What is the reference level for noise measurement, F1A weighted? A. -90 dBm B. -82 dBm C. -67 dBm D. -85 dBm
Description : A measurement of -75 dBm, C-message weighted, would be _________ dBrnc. A. 8 B. 7 C. 9 D. 15
Last Answer : D. 15
Description : 15 dBa F1A weighted, equals ___________. A. -90 dBm B. -82 dBm C. -85 dBm D. -70 dBm
Last Answer : D. -70 dBm
Description : F1A weighting refers to ___________. A. -90 dBm B. dBrnc0 C. dBrnc D. F1A handset
Last Answer : C. dBrnc
Description : The difference between signal strength at a given point and a reference level is________. A. power B. dBm C. level D. ratio
Last Answer : C. level
Description : What is the unit of noise power of psophometer? A. pWp B. dBa C. dBm D. dBrn
Last Answer : A. pWp
Description : The most common unit of noise measurement in white noise voltage testing. A. NPR B. dBm C. dBW D. dBrn
Last Answer : A. NPR
Description : Unit of noise power of psophometer A. dBa B. pWp C. dBm D. dBmO
Last Answer : B. pWp
Description : The most common unit of noise measurement in white noise testing. A. dBw B. dBk C. dBm D. NPR
Last Answer : D. NPR
Description : Noise reduction system used for film sound in movie A. dBx B. dolby C. dBa D. dBm
Last Answer : B. dolby
Description : What is the gain of an antenna over a half-wavelength dipole when it has 6 dB gain over an isotropic radiator? A. 6.0 dB B. 8.1 dB C. 3.9 dB D. 10.0 dB
Last Answer : C. 3.9 dB
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 : ECE Board Exam March 1996 A car horn outdoors produces a sound intensity level of 90 dB at 10 ft away. At this distance, what is the sound power in watt? A. 12 W B. 0.12 W C. 0.012 W D. 1.2 W
Last Answer : C. 0.012 W
Description : A 1 Mhz carrier is amplitude modulated by a pure 200-Hz audio test tone. Which of the following combinations of frequencies represent the total content of the AM signal? A. 1 MHz and 200 Hz B. 1 MHz and 1000.2 kHz C. 999.8 kHz, 1000 kHz, and 1000.2 kHz D. 999.8 kHz and 1000.2 kHz
Last Answer : C. 999.8 kHz, 1000 kHz, and 1000.2 kHz
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 : What is the front-to-back ratio of an antenna which radiates 500 watts in a northernly direction and 50 watts in a southernly direction? A. 25000 dB B. 10 dB C. 100 dB D. 20 dB
Last Answer : B. 10 dB
Description : If an antenna has a gain of 3 dB, it increases the output of the transmitter by A. 10,000 times B. 1000 times C. 100 times D. 1 million times
Last Answer : B. 1000 times
Description : The noise figure of the first circuit in tandem connection is 10.5 dB while its power gain is 15, what is the over all noise figure if the second circuit has a noise figure of 11 dB? A. 11.59 dB B. 11.23 dB C. 10.79 dB D. 10.5 dB
Last Answer : C. 10.79 dB
Description : Three identical circuits having 10 dB signal noise-to-noise ratio each are connected in tandem with each other, what is the overall S/N? A. 5.23 dB B. 14.77dB C. 30 dB D. 40 dB
Last Answer : A. 5.23 dB
Description : What signal-to-noise ratio is required for satisfactory television reception? A. 10 dB B. 30 dB C. 40 dB D. 20 dB
Last Answer : C. 40 dB
Description : What is the effective radiated power of a repeater with 200 watts transmitter power output, 4 dB feline loss, 4 dB duplexer and circulator loss, and 10 dB antenna gain? A. 317 W B. 2000 W C. 126 W D. 260 W
Last Answer : A. 317 W
Description : What is the effective radiated power of a repeater with 100 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 10 dB antenna gain? A. 800 W B. 126 W C. 12.5 W D. 1260 W
Last Answer : B. 126 W
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 : A properly matched transmission line has a loss of 1.5 dB/100m. if 10 W is supplied to one end of the line, how many watts reach the load, 27 m away? A. 10 W B. 7.2 W C. 9.9 W D. 9.1 W
Last Answer : D. 9.1 W
Description : The noise from an airplane engine 100 ft from an observer is found to have an intensity of 45dB. What will be the intensity when the plane flies overhead at an altitude of 1 mi? A. 10.5 dB B. 34.5 dB C. 35 dB D. 20.5 dB
Last Answer : A. 10.5 dB