Description : What is the channel spacing for SITOR frequencies? A. 500 Hz B. 170 Hz C. 300 Hz D. 3 kHz
Last Answer : A. 500 Hz
Description : In what range of frequencies are most omnidirectional horizontally polarized antennas used? A. VHF, UHF B. VLF, LF C. SH, EHF D. MF, HF
Last Answer : A. VHF, UHF
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 : 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 : 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 : A voice-grade circuit using the PTN has an ideal passband of A. 0 to 4 Hz B. 0 to 4 kHz C. 0 to 4 GHz D. 0 to 4 MHz
Last Answer : B. 0 to 4 kHz
Description : Where does the AM broadcast band located in the spectrum band? A. HF band B. VHF band C. LF band D. MF band
Last Answer : D. MF band
Description : Which frequency band is the standard AM radio broadcast? A. HF B. UHF C. MF D. VHF
Last Answer : C. MF
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 : 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 : Nominal voice channel A. 20 to 20 KHz B. 16 to 16 KHz C. 3 to 3 KHz D. 4 KHz
Last Answer : D. 4 KHz
Description : Extra-terrestrial noise is observable at frequencies from A. 0 to 20 KHz B. Above 2 GHz C. 8 to 1.43 GHz D. 5 to 8 GHz
Last Answer : C. 8 to 1.43 GHz
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 : Which of the following frequencies is normally used for distress and safety communications? A. 4209.5 kHz B. 490 kHz C. 518 kHz D. 2174.5 kHz
Last Answer : D. 2174.5 kHz
Description : High quality music only needs frequencies up to A. 10 Hz B. 15 Hz C. 20 kHz D. 15 kHz
Last Answer : D. 15 kHz
Description : Atmospheric noise becomes less severe at frequencies A. above 30 MHz B. below 30 MHz C. above 3000 kHz D. below 3000kHz
Last Answer : A. above 30 MHz
Description : The band of frequencies least susceptible to atmospheric noise and interference is: A. 30 – 300 kHz B. 300 – 3000 kHz C. 3 – 30 MHz D. 300 – 3000 MHz
Last Answer : D. 300 – 3000 MHz
Description : Frequencies above ______ kHz, are referred to as the radio frequencies. A. 20 B. 2 C. 10 D. 200
Last Answer : A. 20
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 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 : The American concert pitch A is equivalent to which if the following frequencies? A. 440 Hz B. 435 Hz C. 260 Hz D. 255 Hz
Last Answer : A. 440 Hz
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 : ECE Board Exam March 1996 What is the purpose of a beat frequency oscillator (BFO)? A. Aid in the reception of weak voice-modulated signals B. Generates a signal, whose frequency is the ... reception D. Generates an output, whose frequency differs from that of the intermediate frequency by 1 kHz
Last Answer : C. Generates a 1kHz note for Morse code reception
Description : Which frequency band is a wavelength of 1200m? a. UHF b. LF c. HF d. MF
Last Answer : b. LF
Description : Suppose a digitized voice channel is made by digitizing 8 kHz bandwidth analog voice signal. It is required to sample the signal at twice the highest frequency (two samples per hertz). What is the bit rate required, if it ... sample requires 8 bits? (A) 32 kbps (B) 64 kbps (C) 128 kbps (D) 256 kbps
Last Answer : (C) 128 kbps
Description : If frequency range of 401.000MHz to 401.050MHz has to be channelized at 12.5 kHz between channel, what is the center of its first channel from the lower limit? A. 401.125MHz B. 401.00625MHz C. 401.025MHz D. 401.0125MHz
Last Answer : B. 401.00625MHz
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 : 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 : A superhet receiver has an IF of 455 kHz and is experiencing image-channel interference on a frequency of 1570 kHz. The receiver is tuned to A. 1115 kHz B. 660 kHz C. 2025 kHz D. 910 kHz
Last Answer : B. 660 kHz
Description : Assume a frequency range of 405.0125 MHz to 405.0875 MHz and 25 kHz channeling plan, determine the center frequency of the second channel from the lower limit. A. 405.030 MHz B. 405.025 MHz C. 405.050 MHz D. 405.075 MHz
Last Answer : C. 405.050 MHz
Description : Assume a frequency range of 401.000 MHz to 401.050 MHz, if you apply 25 kHz channeling plan, determine the center frequency of the first channel from the lower limit. A. 401.010 MHz B. 401.0125 MHz C. 401.025 MHz D. 401.00625 MHz
Last Answer : B. 401.0125 MHz
Description : What is the optimum reverberation time at 500 Hz for a cinema? A. 0.8 – 1.2 sec. B. 0.9 – 1.3 sec. C. 0.6 – 0.8 sec. D. 0.45 – 0.55 sec.
Last Answer : A. 0.8 – 1.2 sec.
Description : The length of a Marconi antenna to operate with 985 kHz is ______. A. 200 ft B. 500 ft C. 250 ft D. 999 ft
Last Answer : C. 250 ft
Description : One of the reasons why FDM is being replaced by TDM is A. noise is amplified with voice when an FDM system is used B. it is difficult to place channels side by side C. there is more time than frequency D. Most available frequencies has been used
Last Answer : A. noise is amplified with voice when an FDM system is used
Description : What is the typical center frequency spacing between adjacent channels (transponders) in satellites? A. 36 MHz B. 40 MHz C. 500 MHz D. 4 MHz
Last Answer : B. 40 MHz
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 : How many voice channels are supported for each 30 KHz radio channel in IS-136? a) Eight b) Thirty c) Three d) Sixteen
Last Answer : c) Three
Description : How many users or voice channels are supported for each 200 KHz channel in GSM? a) Eight b) Three c) Sixty four d) Twelve
Last Answer : a) Eight
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 : 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 : 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 : 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 : Which frequency bands can be refracted during the day by the D layer? A. VLF B. MF C. LF D. Both VLF and LF
Last Answer : D. Both VLF and LF
Description : You are measuring noise in a voice channel with a Lenkurt 601A, F1A weighting network and a flat meter. Your meter reads -47dBm. What is this reading in dBa? A. 77 dBa B. 35 dBa C. 38 dBa D. 32 dBa
Last Answer : C. 38 dBa
Description : How do you transmit through multiplexing, a thousand of voice channel information over a single fiber optic using on e wavelength? A. Polar division B. Time division C. Fiber division D. Frequency division
Last Answer : B. Time division
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 : 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 : 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 : The correct readback of the frequency 123.725 on 25 kHz spacing is: a. 123.725 b. 123.7 c. 12372 d. 123.72
Last Answer : a. 123.725