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 : 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 : How many bits are required to encode 32 level PCM: (1) 6 (2) 5 (3) 4 (4) 3
Last Answer : 5 bits are required to encode 32 level PCM.
Description : 12 voice channels are sampled at 8000 sampling rate and encoded into 8 bit PCM word. Determine the rate of the data stream. a. 354 kbps b. 750 kbps c. 768 kbps d. 640 kbps
Last Answer : c. 768 kbps
Description : A Huffman code: A = 1, B = 000, C = 001, D = 01 ,P(A) = 0.4, P(B) = 0.1, P(C) = 0.2, P(D) = 0.3 The average number of bits per letter is A. 8.0 bit B. 2.0 bit C. 1.9 bit D. 2.1 bit
Last Answer : C. 1.9 bit
Description : A Huffman code: A = 1, B = 000, C = 001, D = 01 ,P(A) = 0.4, P(B) = 0.1, P(C) = 0.2, P(D) = 0.3 The average number of bits per letter is a. 8.0 bit b. 2.0 bit c. 1.9 bit d. 2.1 bit
Last Answer : c. 1.9 bit
Description : What is the frequency range of C-band? A. 8.5 to 12.5 GHz B. 3.4 to 6.425 GHz C. 12.95 to 14.95 GHz D. 27.5 to 31 GHz
Last Answer : B. 3.4 to 6.425 GHz
Description : How many address bits are required to represent a 32 K memory (A) 10 bits. (B) 12 bits. (C) 14 bits. (D) 16 bits.
Last Answer : (D) 16 bits.
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 : ECE Board Exam March 1996 Communications code is ____________. A. eight bits per character B. agreed upon in advance between sender and receiver C. the same in all modern computers D. either seven or eight bits per character
Last Answer : B. agreed upon in advance between sender and receiver
Description : Which standard is utilized in intermodulation noise rates on PCM audio channels? A. CCIT Rec. G.151 B. CCIT Rec. G.172 C. CCIT Rec. G.190 D. CCIT Rec. G.190
Last Answer : B. CCIT Rec. G.172
Description : Which causes a quantization noise in PCM system? A. Serial transmission errors B. The approximation of the quantized signal C. The synchronization between encoder and decoder D. Binary coding techniques
Last Answer : B. The approximation of the quantized signal
Last Answer : The approximation of the quantized signal
Description : Quantizing noise occurs in A. PCM B. PLM C. PDM D. PAM
Last Answer : A. PCM
Description : In SPADE system, how many PCM-encoded voice band channels are there? A. 800 B. 600 C. 300 D. 240
Last Answer : A. 800
Description : ________ is the method of encoding audio signals used in US standard 1544 kbit/s 24 channel PCM systems. A. Shannon’s law B. A-law C. Newton’s law D. Mu-law
Last Answer : D. Mu-law
Description : Steps to follow to produce PCM signal. A. Quantizing, sampling, and coding B. Sampling, quantizing, and coding C. Sampling, coding and quantizing D. Coding, quantizing and coding
Last Answer : B. Sampling, quantizing, and coding
Description : What is the reason why companding is employed in PCM systems? A. To overcome impulse noise in PCM receivers B. To allow amplitude limiting in the receivers C. To solve quantizing noise problem D. To protect small signals in PCM from quantizing distortion
Last Answer : D. To protect small signals in PCM from quantizing distortion
Description : The process of assigning PCM codes to absolute magnitudes A. Overloading B. All of these C. Quantizing D. Multiplexing
Last Answer : C. Quantizing
Description : ECE Board Exam March 1996 Which of the following pulse modulation systems is analog? A. Delta B. Differential PCM C. PWM D. PCM
Last Answer : C. PWM
Description : ECE Board Exam March 1996 According to the Nyquist theorem, the sampling rate that can be used in a PCM system is ________ the highest audio frequency. A. once B. eight times C. twice D. thrice
Last Answer : C. twice
Description : Data rate at which serial PCM bits are clocked out of the PCM encoder onto the transmission line.
Last Answer : line speed
Description : If a fiber optic system has a rise time of 16 ns, the source rise time is 1.5 ns and the detector rise time is 2 ns, what is the cable rise time? A. 14 ns B. 6 ns C. 9 ns D. 12.5 ns
Last Answer : A. 14 ns
Description : What is the frequency range of C-band? A. 10.95 to 14.5 GHz B. 27.5 to 31 GHz C. 3.4 to 6.424 GHz D. 1.53 to 2.7 GHz
Last Answer : C. 3.4 to 6.424 GHz
Description : According to KBP revised radio code which airtime below is classified class D for AM stations? A. 6:00 AM to 12:00 NN B. 12:00 NN to 6:00 PM C. 9:00 PM to 12 Midnight D. 12:00 Midnight to 5:00 AM
Last Answer : D. 12:00 Midnight to 5:00 AM
Description : Determine the dynamic range for a 10 bit sign magnitude code. A. 1023 B. 425 C. 511 D. 756
Last Answer : C. 511
Description : What is the frequency range of an aircraft’s Very High Frequency (VHF) communications? A. 118.000 MHz to 136.975 MHz (worldwide up to 151.975 MHz) B. 108.000 MHz to 117.95 MHz C. 329.15 MHz to 335.00 MHz D. 2.0000 MHz to 29.999 MHz
Last Answer : A. 118.000 MHz to 136.975 MHz (worldwide up to 151.975 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 : Minimum number of bits required to store any 3 digit decima ln umber is equal to (A) 3 (B) 5 (C) 8 (D) 10
Last Answer : Answer: D
Description : I have some matchsticks set up like this: I + XI = X. If you do not know Roman numerals, here is a quick starter: I=1 II=2 III=3 IV=4 V=5 VI=6 VII=7 VIII=8 IX=9 X=10 XI=11 ... are told to move the minimum number of matchsticks to make the question correct. So, how many do you have to move? -Riddles
Last Answer : Most people would get to one move at the least, but the real answer is zero moves. If you rotate the whole question around 180 degrees, it will display this: X = IX + I
Description : A network with bandwidth of 10 Mbps can pass only an average of 12,000 frames per minute with each frame carrying an average of 10,000 bits. What is the throughput of this network ? a. 1 Mbps b. 2 Mbps c. 10 Mbps d. 12 Mbps
Last Answer : b. 2 Mbps
Description : How many bytes of data can be sent in 15 seconds over a serial link with baud rate of 9600 in asynchronous mode with odd parity and two stop bits in the frame? a. 10,000 bytes b. 12,000 bytes c. 15,000 bytes d. 27,000 bytes
Last Answer : b. 12,000 bytes
Description : A network with bandwidth of 10 Mbps can pass only an average of 12,000 frames per minute with each frame carrying an average of 10,000 bits. What is the throughput of this network ? (A) 1 Mbps (B) 2 Mbps (C) 10 Mbps (D) 12 Mbps
Last Answer : (B) 2 Mbps
Description : How much is the required minimum power output of an international AM BC stations? A. 5 kW B. 30 kW C. 10 kW D. 50 kW
Last Answer : D. 50 kW
Description : How many bits are equal to one byte? (1) 8 (2) 10 (3) 12 (4) 14
Last Answer : 8
Description : A data file of 1,00,000 characters contains only the characters g-l, with the frequencies as indicated in table: using the variable-length code by Huffman codes, the file can be encoded with (A) 2,52,000 bits (B) 2,64,000 bits (C) 2,46,000 bits (D) 2,24,000 bits
Last Answer : (D) 2,24,000 bits
Description : A memory management system has 64 pages with 512 bytes page size. Physical memory consists of 32 page frames. Number of bits required in logical and physical address are respectively: (1) 14 and 15 (2) 14 and 29 (3) 15 and 14 (4) 16 and 32
Last Answer : (3) 15 and 14
Description : If a modulating wave is sampled 10 times per cycle with a 5-element binary code, how many bits of information are required to transmit the signal?
Last Answer : 28. 50.
Description : If the purchases made during the year were Rs. 60,000, the balance of stock in trade at the beginning and at the end of the year were Rs. 12,000 and Rs. 9,000 respectively and the gross profit on sales was 1/5th, when which ... year ? (A) Rs. 15,750 (B) Rs. 14,000 (C) Rs. 12,500 (D) Rs. 17,250
Last Answer : Answer: Rs. 12,500
Description : What is the typical number of bits in a static memory location? A. 1 B. 2 C. 16 D. 8
Last Answer : D. 8
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 : 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 : Calculate the energy of the photon of infrared light energy at 1.55µm A. 1.28x10-19 J B. 1.6 x10-19 J C. 1.22 x10-16 J D. 1.9 x10-14 J
Last Answer : A. 1.28x10-19 J
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 : the range of the data 13, 18, 20, 15, 12, 17, 9, 14, 11, and 16 is ________.
Last Answer : the range of the data 13, 18, 20, 15, 12, 17, 9, 14, 11, and 16 is ________.
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 : A mobile satellite array has usually how many elements? A. 6 B. 88 C. 12 D. 14
Last Answer : D. 14
Description : The frequency of Ku band for satellite communications. A. 6/4 GHz B. 14/11 GHz C. 12/14 GHz D. 4/8 GHz
Last Answer : B. 14/11 GHz
Description : The sound intensity received from the nearby jet plane is 12.6 µW/m2 and that from another jet plane some distance away is 0.45 µW/m2 . Find the relative loudness of the two. A. 14.0 dB B. 14.5dB C. 12.5 D. 14.5
Last Answer : B. 14.5dB