Description : What is the deviation ratio for an FM-phone signal having a maximum frequency swing of plus or minus 5 kHz and accepting a maximum modulation rate of 3kHz? A. 60 B. 0.16 C. 0.6 D. 1.66
Last Answer : D. 1.66
Description : What is the approximate bandwidth of an FM system with 10 kHz of modulating frequency and a 150 kHz of frequency deviation? A. 300 kHz B. 320 kHz C. 150 kHz D. 200 kHz
Last Answer : B. 320 kHz
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 : Which determines the number of sideband components of FM? A. Modulation frequency B. Modulation index C. Carrier frequency D. All of these
Last Answer : B. Modulation index
Description : Cellular radios use FM with a maximum deviation of A. ±30 khz B. ±75 khz C. ±25 khz D. ±12 khz
Last Answer : D. ±12 khz
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 : ______ polarization is employed in FM broadcasting A. Horizontal B. Vertical C. Circular D. Bidirectional
Last Answer : A. Horizontal
Description : Which does not use vertical polarization antenna? A. AM Broadcasting B. FM Broadcasting C. Mobile Communications D. Satellite Communications
Last Answer : B. FM Broadcasting
Description : ECE Board Exam March 1996 The method of generating FM used by broadcasting station is A. direct B. all of these C. indirect D. insertion
Last Answer : C. indirect
Description : Emission on a frequency or frequencies immediately outside the necessary bandwidth which result from the modulation process except spurious emission. A. Radiation B. Noise C. Out of the band D. Interference
Last Answer : C. Out of the band
Description : The modulation index of a FM Signal having modulating frequency 2 KHz and Max deviation is 10 KHz, is: - a) 2 b) 5 c) 3 d) 4
Last Answer : The modulation index of a FM Signal having modulating frequency 2 KHz and Max deviation is 10 KHz, is: - 5
Description : A radio station is broadcasting at 3750 khz (kilohertz). This station would be found in which radio band? w) 20 meter x) 40 meter y) 80 meter z) 160 meter
Last Answer : ANSWER: Y -- 80 METER
Description : What is the spectrum of stereophonic FM signal? A. 19 to 38 kHz B. 30 to 53 kHz C. 59.5 to 74.5 kHz D. 88 to 108 MHz
Last Answer : B. 30 to 53 kHz
Description : The frequency spectrum of the stereophonic FM signal. A. 67 kHz B. 59.5 to 74.5 kHz C. 19 to 38 kHz D. 30 to 53 kHz
Last Answer : D. 30 to 53 kHz
Description : What is the carrier frequency of supergroup 10? A. 2724 kHz B. 2356 kHz C. 2108 kHz D. 3100 kHz
Last Answer : D. 3100 kHz
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 : How wide is the spectrum bandwidth of a single GSM carrier? A. 100 kHz B. 200 kHz C. 50 kHz D. 16 kHz
Last Answer : B. 200 kHz
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 modulation is normally used with digital data? A. AM B. FM C. SSB D. QPSK
Last Answer : D. QPSK
Description : What type of modulation is used on voice and video signals? A. AM B. FM C. SSB D. QPSK
Last Answer : B. FM
Description : Both frequency and phase modulation utilize ________ modulation A. Phase B. AM and FM C. Digital D. Angle
Last Answer : D. Angle
Description : What is the channel number of an FM station with a carrier frequency of 99.5 MHz? A. 256 B. 258 C. 257 D. 259
Last Answer : B. 258
Description : The carrier waves used for the radio transmission have frequency upto A. 15 KHz B. 30 KHz C. 90 KHz D. 150 KHz
Last Answer : ANSWER: B
Description : What is the term used to describe a spread spectrum communications system where the center frequency if a conventional carrier is altered many time per second in accordance with a pseudo ... hopping B. Direct sequence C. Time-domain frequency modulation D. Frequency compandored spread spectrum
Last Answer : A. Frequency hopping
Description : What is meant by the term deviation ratio? A. The ratio of the carrier center frequency to the audio modulating frequency B. The ratio of the highest audio modulating frequency to the ... audio modulation frequency D. The ratio of the audio modulating frequency to the center carrier frequency
Last Answer : C. The ratio of the maximum carrier frequency deviation to the highest audio modulation frequency
Description : In radio regulation, the first symbol in the designation of radio emission is ______. A. Bandwidth B. Nature of signal(s) modulation the main carrier C. Type of modulation of the main carrier D. Type of information to be transmitted
Last Answer : C. Type of modulation of the main carrier
Description : This is referred to a product of simultaneous frequency and amplitude modulation or a carrier frequency variation which produces unwanted distortion. A. Absorption modulation B. Simultaneous modulation C. Dynamic instability D. Series modulation
Last Answer : C. Dynamic instability
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 : In amplitude modulation technique the unmodulated carrier is referred to as having ______. A. 100% modulation B. 0% modulation C. 50% modulated D. Over modulated
Last Answer : B. 0% modulation
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
Description : An AM transmitter is rated 100W at 100% modulation. How much power required for the carrier? A. 33.33 W B. 66.66 W C. 83.33 W D. 100 W
Last Answer : B. 66.66 W
Description : Average power of a radio transmitter supplied to the antenna transmission line by a transmitter during one radio frequency cycle taken under the condition of no modulation. A. Peak envelop power B. Rated power C. Carrier power D. Mean power
Last Answer : C. Carrier power
Description : Modulation in which the modulated wave is always present. A. Carrier modulation B. Front-end C. Continuous modulation D. Log-periodic modulation
Last Answer : C. Continuous modulation
Description : The third symbol in the designation of radio emission under the ITU rules refers to A. Type of the modulation of the main carrier B. Bandwidth C. Nature of the signals modulating the main carrier D. Type of information to be transmitted
Last Answer : D. Type of information to be transmitted
Description : The first symbol in the designation of radio emission under the ITU rules to A. Nature of signals modulating the main carrier B. Type of information to be transmitted C. Bandwidth D. Type of modulation of the main carrier
Last Answer : D. Type of modulation of the main carrier
Description : Modulation means A. Varying of information B. Utilization of a single transmission channel to carry multiple signals C. Varying of some parameters of a carrier such as its amplitude to transmit information D. Transmit pulses in DC form on a copper wire
Last Answer : C. Varying of some parameters of a carrier such as its amplitude to transmit information
Description : At 100% modulation, the sum fo the effective voltages in both sidebands is equal to ______% of the unmodulated carrier voltage. A. 50 B. 71 C. 100 D. 25
Last Answer : B. 71
Description : Which of the following is not a baseband signal modulation? A. RF carrier B. Video System C. Audio signal D. Binary coded pulses
Last Answer : A. RF carrier
Description : If the percentage modulation of an AM amplifier is 88% and the modulating signal is 1 volt, the carrier has an amplitude of _______________. A. 1.14 volts B. 0.88 volt C. 1.88 volts D. 0.12 volt
Last Answer : A. 1.14 volts
Description : Three audio waves with 100,200 and 300 volts amplitude respectively, simultaneously modulate a 450 volts carrier. What is the total percent of modulation of the AM wave? A. 69 % B. 115.5 % C. 50% D. 83%
Last Answer : D. 83%
Description : ECE Board Exam March 1996 The letter-number designation B8E is a form of modulation also known as ___________. A. pilot carrier system B. independent sideband emission C. lincomplex D. vestigial sideband transmission
Last Answer : B. independent sideband emission
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 : The extremely high frequency (EHF) band is in the radio spectrum range of _______. A. 30 to 300 kHz B. 30 to 300 GHz C. 3 to 30 MHz D. 3 to 30 GHz
Last Answer : B. 30 to 300 GHz
Description : Compare narrow band FM with wide-band FM w.r.t. following points. (i) Modulation index (ii) Maximum deviation (iii)Range of modulating frequency (iv)Application
Last Answer : Sr. No Parameters Narrow band FM Wide band FM 1 Modulation index Less than or slightly greater than 1 Greater than 1 2 Maximum deviation ... like police wireless, ambulance etc. Entertainment broadcasting can be used for high quality music transmission
Description : Compare AM with FM with respect to following points: a) Definition. b) Modulation index. c) Bandwidth. d) Side band.
Last Answer : Parameters AM FM Definition It is the process in which the amplitude of carrier signal is varied in accordance with the instantaneous value of modulating signal keeping frequency and ... frequency deviation. Side band There are two sidebands Infinite number of sideband
Description : One of the FM signal generator control which varies the phase of the modulating voltage applied to the oscillator of the sweep generator A. Band control B. Phase control C. Marker amplitude control D. Sweep output control
Last Answer : B. Phase control
Description : Which of the following filters block FM radio band for TV channels (2 to 13)? A. High-pass filter B. Band reject filter C. Low-pass filter D. Band-pass filter
Last Answer : B. Band reject filter
Description : The allowable deviation ratio of commercial FM broadcast. A. 25 B. 15 C. 5 D. 75
Last Answer : C. 5
Description : The noise output of a resistor is amplified by a noiseless amplifier having a gain of 60 and a bandwidth of 20 kHz. A meter connected at the output of the amplifier reads 1mV RMS. If the bandwidth of the amplifier is reduced to ... does the meter read now? A. 0.5 mV B. 0.5 µV C. 5.0 mV D. 5.0 µV
Last Answer : A. 0.5 mV
Description : What is the spectrum range of U600 mastergroup? A. 60 – 108 kHz B. 564 – 3084 kHz C. 312 – 552 kHz D. 60 -2788 kHz
Last Answer : B. 564 – 3084 kHz