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 : The signal to noise ratio that is required for a satisfactory television reception. A. 30 dB B. 40 dB C. 10 dB D. 20 dB
Last Answer : B. 40 dB
Description : What is the quantization signal-to-noise ratio if an 8-bit PCM code is used? A. 40 dB B. 50 dB C. 60 dB D. 65 dB
Last Answer : B. 50 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 : The signal in a channel is measured to be 23 dB while noise in the same channel is measured to be 9 dB. The signal to noise ratio therefore is __________. A. 9/23 B. 23/9 C. 32 dB D. 14 dB
Last Answer : D. 14 dB
Description : A coherent binary phase shift keyed BPSK transmitter operates at a bit rate of 20 Mbps with a carrier to noise ratio C/N of 8.8dB. Find Eb/No. A. 73 dB B. 62.4 dB C. 81.8 dB D. 8.8 dB
Last Answer : D. 8.8 dB
Description : Three telephone circuits, each having an S/N ratio of 44 dB, are connected in tandem. What is the overall S/N ratio? A. 44 dB B. 39.2 dB C. 41 dB D. 43.52 dB
Last Answer : B. 39.2 dB
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 : What is typical loudness level of an acoustic guitar 1 foot away? A. 60dB B. 100dB C. 80dB D. 40dB
Last Answer : C. 80dB
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 : You are measuring noise at a +3 dB level point, using the Lenkurt 601A, F1A weighting network, and a flat meter. The meter reading is -57dBm. This is ________dBa0. A. 20 B. 15 C. 25 D. 17
Last Answer : C. 25
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
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 : A dipole antenna requires to be fed with 20 kW of power to produce a given signal strength to a particular distant point. If the addition of a reflector makes the same field strength available with an input power of 11kW ... Gain referred to this particular dipole). A. 4.75 B. 2.6 C. 1.81 D. 4.24
Last Answer : B. 2.6
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 : A dipole antenna requires to be feed with 20 kW of power to produce a given signal strength to a particular distant point. If the addition of a reflector makes the same field strength available with an input power of 11 ... ( Gain referred to this particular dipole) A. 4.24 B. 1.81 C. 4.75 D. 2.6
Last Answer : D. 2.6
Description : What region around a broadcasting transmitter in which satisfactory reception of broadcasting signal is not obtained? A. Fringe area B. Primary are C. Secondary area D. Tertiary area
Last Answer : A. Fringe area
Description : What is the power loss of a telephone hybrid? A. 6 dB B. 2 dB C. 3 dB D. 1 dB
Last Answer : C. 3 dB
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 : if noise voltage =120 mv and signal voltage = 80 v , S/N ratio in dB is?
Last Answer : Answers is the place to go to get the answers you need and to ask the questions you want
Description : What is the number of levels required in a PCM system with S/N ratio of 40 dB? A. 64 B. 128 C. 256 D. 512
Last Answer : B. 128
Description : Which noise figure represents the lowest noise in receiver? A. 1.6 dB B. 2.1 dB C. 2.7 dB D. 3.4 dB
Last Answer : A. 1.6 dB
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 : Interfering effect of noise, C message weighted, is _________. A. dBa B. dBm C. dBmc D. dB
Last Answer : C. dBmc
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 : 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 : Stacking antenna elements A. increases sensitivity to weak signals B. will suppress odd harmonics C. decrease signal to noise ratio D. increases selectivity
Last Answer : A. increases sensitivity to weak signals
Description : Indicate the false statement. Noise figure is defined as A. the ratio of the S/N power supplied at the input terminal of a receiver or amplifier to the S/N power supplied to the output or ... under test, both working at the same temperature over the same bandwidth and fed from the same source
Last Answer : C. an unwanted form of energy tending to interfere with the proper and easy reception and reproduction of wanted signals
Description : Where is the noise generated that primarily determines the signal-to-noise ratio in a VHF (150MHz) marine-band receiver? A. Man-made noise B. In the atmosphere C. In the receiver front end D. In the ionosphere
Last Answer : C. In the receiver front end
Description : What causes image interference? A. Low gain B. High IF C. Poor front-end selectivity D. Low signal-to-noise ratio
Last Answer : C. Poor front-end selectivity
Description : What bandwidth is needed to support a capacity of 128 kbps when the signal power to noise power ratio in decibels is 100? A. 19224 Hz B. 3853 Hz C. 19244 Hz D. 3583 Hz
Last Answer : B. 3853 Hz
Description : What is meant by the term modulation index? A. The processor index. B. The ratio between the deviation of a frequency modulated signal and the modulating frequency. C. The FM signal-to-noise ratio. D. The ratio of the maximum carrier frequency deviation to the highest audio modulating frequency.
Last Answer : B. The ratio between the deviation of a frequency modulated signal and the modulating frequency.
Description : Where is the noise generated that primarily determines the signal-to-noise ratio in a VHF (150 MHz) marine-band receiver? A. In the ionosphere B. In the receiver rear end C. In the receiver front end D. In the atmosphere
Description : ______ is a term in the test language for noise testing in telephone circuits that means a one-syllable word consisting of a consonant, a vowel, and another consonant. A. Logatom B. Nosfer C. Ore D. Belcore
Last Answer : A. Logatom
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 : The conversion of digital signal into analog for purposes of transmitting into the telephone line is done through ______. A. ISDN B. Radio C. RS232C D. Modem
Last Answer : D. Modem
Description : What is the advantage of sidetone? A. High transmission efficiency B. Results to a strengthened signal C. No energy dissipation D. Assures that the telephone is working
Last Answer : D. Assures that the telephone is working
Description : Atmospheric noise or static is not a great problem A. at frequencies below 20 MHz B. at frequencies below 5 MHz C. at frequencies above 30 MHz D. at frequencies above 1 MHz
Last Answer : C. at frequencies above 30 MHz
Description : Two tape recorders have signal-to-noise ratios (SNRs) of 25-dB RMS and 35-dB RMS respectively. Which of the SNRs can record and reproduce the widest range of input signals and why?
Last Answer : 35-dB RMS because the highest SNR can always record and reproduce the widest range of input signals.
Description : What is the effective radiated power of a repeater with 50 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 7 dB antenna gain? A. 300 W B. 315 W C. 31.5 W D. 69.9 W
Last Answer : C. 31.5 W
Description : What is the effective radiated power of a repeater with 50 watts transmitter power output \, 4 dB feedline loss, 3 dB duplexer and circulator loss, and 6 dB antenna gain? A. 158 W B. 39.7 W C. 251 W D. 69.9 W
Last Answer : B. 39.7 W
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 the required quality factor for an SSB filter with the following data: center frequency= 1 MHz, the desired attenuation level of the unwanted sideband= 80 dB and the separation between sidebands= 200 Hz? A. 1,250 B. 12,500 C. 125,000 D. 25,000
Last Answer : C. 125,000
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 : What is the data rate in Mbps of a single satellite transponder considering an S/N of 30 dB? A. 35.8 B. 3.58 C. 358 D. 3580
Last Answer : C. 358
Description : Determine the gain of a 6 ft. parabolic dish operating at 1800 MHz. A. 30 dB B. 11.2 dB C. 15.5 dB D. 28.17 dB
Last Answer : D. 28.17 dB
Description : The total space loss of transmission and reception for two ground stations with uplink frequency 8GHz and a downlink of 6 GHz with angle of elevations of 3˚ and 7˚ A respectively is A. 403 dB B. 100 dB C. 20 dB D. 215 dB
Last Answer : A. 403 dB
Description : For a loudness level between 110 and 120 dB, the maximum daily exposure limit is ____ minute (s). A. 1 B. 60 C. 20 D. 45
Last Answer : A. 1
Description : At what loudness level do pitch (in mels) and frequency (in Hz) are numerically equal? A. 0 dB B. 20 dB C. 60 dB D. 40 dB
Last Answer : D. 40 dB
Description : Noise occurring in the presence of signal resulting from a mismatch between the exact value of an analog signal and the closet available quantizing step in a digital coder. A. Quantizing noise B. Thermal noise C. Impulse noise D. Crosstalk
Last Answer : A. Quantizing noise