Description : What is the reference frequency of CCIT phosphomeric noise measurement? A. 800 Hz B. 1000 Hz C. 1500 Hz D. 3400 Hz
Last Answer : A. 800 Hz
Description : The CCITT standard bandwidth for speech is: (A) 20000 Hz (B) 15000 Hz (C) 7000 Hz (D) 3400 Hz
Last Answer : (D) 3400 Hz
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 : What is the channel bandwidth of a standard analogue telephone system? A. 300-500 Hz B. 1200 kHz C. 100-300 Hz D. 300-3400 Hz
Last Answer : D. 300-3400 Hz
Description : The laser frequency when the light has the wavelength 800 nm is a. 375 x 10^12 Hz b. 475 x 10^15 Hz c. 375 x 10^9 Hz d. 375 x 10^18 Hz
Last Answer : a. 375 x 10^12 Hz
Description : What is the reference level for noise measurement, F1A weighted? A. -90 dBm B. -82 dBm C. -67 dBm D. -85 dBm
Last Answer : D. -85 dBm
Description : A frequency of 3000 Hz has how many octaves above 1000 Hz? A. 1.6 octaves B. 2.1 octaves C. 1 octave D. 3 octaves
Last Answer : A. 1.6 octaves
Description : The ratio of the level of the modulated output of a transmitter under conditions of standard test modulation to the level of the demodulated output with no modulation applied both measured with the ... . Reference audio output B. None of these C. Audio frequency response D. Residual noise level
Last Answer : D. Residual noise level
Description : What does the noise weighting curve shows? A. Noise signals measured with a 144 handset B. Power levels of noise found in carrier systems C. The interfering effect of other frequencies in a voice ... a reference frequency of one kilohertz D. Interfering effects of signals compared with a 3-kHz tone
Last Answer : C. The interfering effect of other frequencies in a voice channel compared with a reference frequency of one kilohertz
Description : Which of the following is the new name of CCITT? A. ITU-T B. ITU-R C. ITU-S D. ITU-D
Last Answer : A. ITU-T
Description : ECE Board Exam March 1996 The number of voice band channels in master group per CCITT standard is __________. A. 300 B. 480 C. 600 D. 12
Last Answer : A. 300
Description : What is the phase delay of an 800 Hz voice signal if the phase shift is 15 degrees? A. 1.25 µsec B. 52 µsec C. 83.33 µsec D. 26 µsec
Last Answer : B. 52 µsec
Description : ____________ is the out-of-band signaling between toll central offices (Bell System Standard) A. 2,000 Hz B. 800 Hz C. 3,835 Hz D. 3700 Hz
Last Answer : D. 3700 Hz
Description : The total noise power present in a 1-Hz bandwidth . A. Noise density B. Noise figure C. Noise limit D. Noise intensity
Last Answer : A. Noise density
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 : Flicker noise is a poorly understood form of noise which may be completely ignored about above ____. A.100 Hz B. 200 Hz C. 400 Hz D. 500 Hz
Last Answer : D. 500 Hz
Description : For protection of level crossing gate in an emergency on BG double line the Gateman should place one detonator at one place and 3 detonators at a subsequent place at a distance of ------- a) and------ ... c) 500 meters and 1000 meters d) 600 meters and 1200 meters* e) 800 meters in 1500 meters
Last Answer : d) 600 meters and 1200 meters*
Description : How many voice signals (4 kHz max.) would fit into a 5 MHz spectrum? A. 1250 B. 500 C. 1000 D. 1500
Last Answer : A. 1250
Description : At what distance is VHF propagation normally limited? A. Around 500 miles B. Around 1500 miles C. Around 2000 miles D. Around 1000 miles
Last Answer : A. Around 500 miles
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 : 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 : 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 : What is the optimum reverberation time at 500 to 1000 Hz of an auditorium? A. 0.9 to 1.1 s B. 1.4 to 1.6 s C. 1.5 to 1.6 s D. 1.6 to 1.8 s
Last Answer : D. 1.6 to 1.8 s
Description : What is the reliable measurement for comparing amplifier noise characteristics? A. Thermal agitation noise B. Noise factor C. Noise margin D. Signal-to-noise
Last Answer : B. Noise factor
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 : 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 that occurs via capacitive or inductive coupling in a cable. A. Crosstalk B. Quantizing noise C. Reference noise D. Tone interference
Last Answer : A. Crosstalk
Description : Standard design reference for environmental noise temperature. A. 300 K B. 290 K C. 32 ˚F D. 212˚F
Last Answer : B. 290 K
Description : What is the reference noise level? A. 10 pW B. 0 dBm C. 1mW D. -90 dBm
Last Answer : D. -90 dBm
Description : Reference temperature use in noise analysis A. 75 K B. 250 K C. 290 K D. 300 K
Last Answer : C. 290 K
Description : What is the reference noise temperature in degrees Celsius? A. 17 B. 273 C. 25 D. 30
Last Answer : A. 17
Description : Reference noise temperature. A. 70 deg F B. 30 deg C C. 290 Kelvin D. 25 deg C
Last Answer : C. 290 Kelvin
Description : If a DNA contains 1000 base pairs, what would be its length? a) 3400 Å b) 34000 Å c) 6800 d) 1000 Å
Last Answer : a) 3400 Å
Description : The laser frequency when the light has the wavelength 800 nm is ∙ a. 375 x 1012 Hz ∙ b. 475 x 1015 Hz ∙ c. 375 x 109 Hz ∙ d. 375 x 1018 Hz
Last Answer : d. 375 x 1018 Hz
Description : What is the photon energy for an infrared wave with frequency of 1012 Hz? a. 10.6 x 1034 joules b. 6.63 x 10-34 joules c. 6.63 x 10-22 joules d. 10.6 x 1022 joules
Last Answer : c. 6.63 x 10-22 joules
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 : In acoustics, if the volume of the room is 200 m3 then at what frequency the coefficient of absorption is measured? A. 120 kHz B. 120 Hz C. 100 Hz D. 150 Hz
Last Answer : B. 120 Hz
Description : What is the typical frequency used for communicating to submerged submarines? A. 100 Hz B. 500 Hz C. 4 kHz D. 200 Hz
Last Answer : A. 100 Hz
Description : What frequency is 10 octaves above 30 Hz? A. 30.72 kHz B. 30 kHz C. 300 Hz D. 307.2 kHz
Last Answer : A. 30.72 kHz
Description : What is the frequency of a 2-cm sound wave in sea water at 25˚C? A. 76 kHz B. 76 Hz C. 76 MHz D. 76 mHz
Last Answer : A. 76 kHz
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 : The frequency tolerance of an AM radio broadcast station A. 200 Hz B. 2000 Hz C. 20 Hz D. 2 Hz
Last Answer : C. 20 Hz
Description : The lowest frequency produced by an instrument. A. Harmonic B. Fundamental C. Midrange D. 0 Hz
Last Answer : B. Fundamental
Description : A carrier signal has ______. A. Constant peak amplitude B. The information C. Frequency range 20-20000 Hz D. A varying amplitude
Last Answer : A. Constant peak amplitude
Description : The midrange frequency range of sound is from A. 256 to 2048 Hz B. 2048 to 4096 Hz C. 512 to 2048 Hz D. 16 to 64 Hz
Last Answer : A. 256 to 2048 Hz
Description : The width of the frequency band which is just sufficient to ensure the transmission of information at the rate and with the quality required under a specified condition and class of emission. A. Occupied bandwidth B. Reference frequency C. Necessary bandwidth D. Frequency tolerance bandwidth
Last Answer : C. Necessary bandwidth
Description : Human ear is most sensitive to noise in the following frequency ranges: (A) 1-2 KHz (B) 100-500 Hz (C) 10-12 KHz (D) 13-16 KHz
Last Answer : (A) 1-2 KHz
Description : Crosstalk due to incomplete suppression of sidebands or to intermodulation of two or more frequency-multiplexed channels which is unintelligible is classified as A. Impulse noise B. Thermal noise C. Quantizing noise D. Miscellaneous noise
Last Answer : D. Miscellaneous noise
Description : An amplifier operating over the frequency range of 455 to 460 kHz has a 200 kΩ input resistor. What is the RMS noise voltage at the input to this amplifier if the ambient temperature is 17˚C ? A. 40 µV B. 4.0 µV C. 400 µV
Last Answer : B. 4.0 µV