Description : To ensure the accuracy of a transmission, what is the minimum number of times a modulating wave should be sampled in pulse modulation?
Last Answer : 2.5 times the highest modulating frequency.
Description : Value of sampled signal is used to produce a A. binary number B. decimal number C. octal number D. all of above
Last Answer : binary number
Description : What happens to an fm signal as you increase the frequency of the modulating signal?
Last Answer : Both the bandwidth and the number of significant sidebands increase.
Description : The analog signal given below is sampled by 600 samples per second for m(t) = 3 sin 500 pt + 2 sin 700 pt then folding frequency is: (1) 500 Hz (2) 700 Hz (3) 300 Hz (4) 1400 Hz
Last Answer : The analog signal given below is sampled by 600 samples per second for m(t) = 3 sin 500 pt + 2 sin 700 pt then folding frequency is: 300 Hz
Description : In radio signal emission designation, the fifth symbol means A. Details of signals B. Type of information transmitted C. Nature of multiplexing D. Nature of signal modulating the main carrier
Last Answer : C. Nature of multiplexing
Description : In_____ transmission, the frequency of the carrier signal is modulated to follow the changing voltage level (amplitude)of the modulating signal. The peak amplitude and phase of the carrier signal remainconstant,but as ... of thecarrier changes correspondingly. A) AM B) PM C) FM D) none of the above
Last Answer : FM
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 : Consider a CSMA/CD network that transmits data at a rate of 100 Mbps (108 bits per second) over a 1 km (kilometre) cable with no repeaters. If the minimum frame size required for this network is 1250 bytes, what is the signal speed (km/sec) in the cable? a. 8000 b. 10000 c. 16000 d. 20000
Last Answer : d. 20000
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 : The analog signal needs to be sampled at a minimum sampling rate of: (A) 2fs (B) 1/(2fs) (C) fs/2 (D) 2/fs
Last Answer : (A) 2fs
Description : A pulse modulation technique as the width of a constant amplitude pulse is varied proportional to the amplitude of the analog signal at the time the signal is sampled.
Last Answer : PWM, PLM, PDM
Description : Explain flat top sampling with circuit diagram.Draw flat top sampled signal.
Last Answer : Flat top sampling: In flat top sampling, the top of the samples remains constant and equal to the instantaneous value of the modulating signal at the start of the sampling. Thus the ... the sampled signal and the pulse signal. Flat top sampling is mostly used in digital transmission
Description : If a signal band limited to fm is sampled at a rate less than 2fm, then the constructed signal will be A) Large in amplitude B) Small in amplitude C) Distorted D) Distortion less
Last Answer : If a signal band limited to fm is sampled at a rate less than 2fm, then the constructed signal will be Distorted
Description : What does the simplest diode detector use to reproduce the modulating frequency?
Last Answer : The modulation envelope.
Description : . What is the function of the modulating circuit?
Last Answer : To produce an af (or video) signal that can be superimposed on the rf signal produced by the oscillator.
Description : With a single modulating tone, what is the amplitude of the sideband frequencies at 100-percent modulation?
Last Answer : One-half the amplitude of the carrier.
Description : Deemphasis in the receiver in effect attenuates modulating signal components and noise in what frequency range? A. dc B. low C. intermediate D. high
Last Answer : D. high
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 : 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 : 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 : In_____ transmission, thephaseof the carrier signal is modulated to follow the changingvoltage level (amplitude) of the modulating signal. A) AM B) PM C) FM D) none of the above
Last Answer : PM
Description : In_____ transmission, thecarrier signal is modulated so that its amplitude varies with the changing amplitudes of the modulating signal. A) AM B) PM C) FM D) none of the above
Last Answer : AM
Last Answer : In communication systems, the modulating signal is also called base band signal.
Description : Group of binary bits(0&1) is known as: a. Binary code b. Digit code
Last Answer : a. Binary code
Description : Let C be a binary linear code with minimum distance 2t + 1 then it can correct upto _____ bits of error. a. t + 1 b. t c. t - 2 d. t / 2
Last Answer : b. t
Description : Let C be a binary linear code with minimum distance 2t + 1 then it can correct upto ............bits of error. (1) t + 1 (2) t (3) t - 2 (4) t/2
Last Answer : (2) t
Description : Consider a source with symbols A, B, C, D with probabilities 1/2, 1/4, 1/8, 1/8 respectively. What is the average number of bits per symbol for the Huffman code generated from above information? (A) 2 bits per symbol (B) 1.75 bits per symbol (C) 1.50 bits per symbol (D) 1.25 bits per symbol
Last Answer : (B) 1.75 bits per symbol
Description : Communication satellite are used to a) Transmit communication signal only b)Receive Communication signal only c)Receive and redirect communication signal d)Provides information of natural resources only
Last Answer : c)Receive and redirect communication signal
Description : Communication satellites are used to: (1) To transmit communication signals (2) To receive and redirect communication signals (3) To only receive communication signal (4) To provide information of national sources only
Last Answer : To receive and redirect communication signals
Description : An analog signal has a bit rate of 6000 bps and a baud rate of 2000 baud. How many data elements are carried by each signal element ? (A) 0.336 bits/baud (B) 3 bits/baud (C) 120,00,000 bits/baud (D) None of the above
Last Answer : (B) 3 bits/baud
Description : The bits are shifted and the first flip-flop receives its binary information from the____ a. Serial output b. Serial input c. Both d. None
Last Answer : b. Serial input
Description : The synchronous modems are more costly than the asynchronous modems because a. they produce large volume of data b. they contain clock recovery circuits c. they transmit the data with stop and start bits d. they operate with a larger bandwidth e. none of above
Last Answer : they contain clock recovery circuits
Description : The synchronous modems are more costly than the asynchronous modemsbecause A. they produce largevolumeof data B. they contain clock recovery circuits C. they transmit thedata with stop and start bits. D. they operate witha largerbandwidth E. None of the above
Description : In NRZ code, does the presence of a high-light level in the bit duration represent a binary 1 or a binary 0?
Last Answer : Binary 1.
Description : What is the minimum number of bits required in a PCM code for a range of 10,000? A. 12 B. 9 C. 14 D. 10
Last Answer : C. 14
Description : Minimum number of bits required to represent maximum value of given analogue signal with 0.1% accuracy is: a. 8 bits b. 9 bits c. 10 bits d. 12 bits
Last Answer : 10
Description : In the inverting configuration, what is the voltage (for all practical purposes) at the inverting input to the operational amplifier if the input signal is a 1-volt, peak-to-peak sine wave?
Last Answer : 0 volts.
Description : When measuring harmonic distortion, you set the signal generator to input a 15-kHz test signal. To what frequency should you set the wave analyzer?
Last Answer : 45 kHz.
Description : An analog signal carries 4 bits in each signal unit. If 1000 signal units are sent per second, then baud rate and bit rate of the signal are ............... and .............. (A) 4000 bauds \ sec & ... (B) 2000 bauds \ sec & 1000 bps (C) 1000 bauds \ sec & 500 bps (D) 1000 bauds \ sec & 4000 bps
Last Answer : (D) 1000 bauds \ sec & 4000 bps Explanation: Bit rate is the number of bits per second. Baud rate is the number of signal units per second. Baud rate is less than or equal to the bit rate. Baud rate = 1000 bauds per second (baud/s) Bit rate = 1000 x 4 = 4000 bps
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 : Define the term 'sample rate'. A. Snapshots of sound are taken as the wave cannot be represented as a series of continuous changes. B. The number of samples taken each second C. The number of bits used per second of audio D. The number of bits available for each clip
Last Answer : B. The number of samples taken each second
Description : If a wave's electric lines of force rotate through 360 degrees with every cycle of rf energy, what is the polarization of this wave?
Last Answer : Circular polarization.
Description : In applications where electronic waveforms are displayed on a CRT screen, the input signal is normally applied to what CRT element?
Last Answer : The vertical-deflection plate.
Description : . What type of synchro system is used to transmit very large quantities?
Last Answer : A tri-speed synchro system.
Description : During which of the transmit or receive cycles are both the tr and atr tubes of a parallelconnected duplexer ionized (arcing)?
Last Answer : Transmit.
Description : What characteristic allows the same antenna to both transmit and receive?
Last Answer : Reciprocity.
Description : A substance that is unable to transmit any light waves is known as what type of substance?
Last Answer : Opaque.
Description : The parasitic array can be rotated to receive or transmit in different directions. What is the name given to such an antenna?
Last Answer : Rotary array.
Description : Number of bits per symbol used in Baudot code is a. 7 b. 5 c. 8 d. 9
Last Answer : 5