Deck 3: Waveform Logic, Pcm Encoding, Vocoder Analysis, and Antenna Radiations

Question 1

In which waveform logic 1 is represented by equal amplitude alternating pulses?

A)unipolar rz
B)bipolar rz
C)rz-ami
D)manchester coding

Answer 1

rz-ami

Question 2

The signals which are obtained by encoding each quantized signal into a digital word is called as

A)pam signal
B)pcm signal
C)fm signal
D)sampling and quantization

Answer 2

pcm signal

Question 3

The length of the code-word obtained by encoding quantized sample is equal to

A)l=log(to the base 2)l
B)l=log(to the base 10)l
C)l=2log(to the base 2)l
D)l=log(to the base 2)l/2

Answer 3

l=log(to the base 2)l

Question 4

In PCM encoding, quantization level varies as a function of_________      

A)frequency
B)amplitude
C)square of frequency
D)square of amplitude

Question 5

What is bit depth?

A)number of quantization level
B)interval between two quantization levels
C)number of possible digital values to represent each sample
D)none of the mentioned

Question 6

Choosing a discrete value that is near but not exactly at the analog signal level leads to

A)pcm error
B)quantization error
C)pam error
D)sampling error

Question 7

In PCM the samples are dependent on

A)time
B)frequency
C)quanization leavel
D)interval between quantization level

Question 8

DPCM encodes the PCM values based on

A)quantization level
B)difference between the current and predicted value
C)interval between levels
D)none of the mentioned

Question 9

Delta modulation uses_________bits per sample.

A)one
B)two
C)four
D)eight

Question 10

Sample resolution for LPCM          bits per sample.

A)8
B)16
C)24
D)all of the mentioned

Question 11

Adaptive DPCM is used to

A)increase bandwidth
B)decrease bandwidth
C)increase snr
D)none of the mentioned

Question 12

Vocoders analyse the speech signals at

A)transmitter
B)receiver
C)channel
D)if filter

Question 13

Vocoders_________          the voice at the receiver.

A)analyse
B)synthesize
C)modulate
D)evaluate

Question 14

Which of the following is not a vocoding system?

A)linear predictive coder
B)channel vocoder
C)waveform coder
D)formant vocoder

Question 15

Which of the following pronunciations lead to voiced sound?

A)'f'
B)'s'
C)'sh'
D)'m'

Question 16

Channel vocoders are the time domain vocoders.

Question 17

__________ is often called the formant of the speech signal.

A)pitch frequency
B)voice pitch
C)pole frequency
D)central frequency

Question 18

Formant vocoders use large number of control signals.

Question 19

Cepstrum vocoder uses_________          

A)wavelet transform
B)inverse wavelet transform
C)cosine transform
D)inverse fourier transform

Question 20

The real part of an antenna's input impedance is due to_________      

A)swr
B)radiated signal
C)reflected signal
D)refracted signal

Question 21

What is the other name for half-wave dipole antenna?

A)helical antenna
B)isotropic antenna
C)hertz antenna
D)maxwell antenna

Question 22

Measured on the ground, the field strength of a horizontally polarized half wave dipole antenna is strongest_________      

A)in one direction
B)in two directions
C)depends on the number of elements
D)depends on the shape of antenna

Question 23

When an antenna radiates more energy in one direction than in other directions, it is called_________      

A)selectivity
B)directivity
C)active antenna
D)resonance

Question 24

What is the full form of ERP?

A)effective radiated power
B)effective reflected power
C)equivalent radiated power
D)equivalent reflected power