21. For a stationary process, the autocorrelation function depends on

A. Time
B. Time difference
C. Does not depend on the time
D. None of the mentioned

Answer: B

The autocorrelation function depends on the time difference between t1 and t2.

22. The autocorrelation function is maximum at

A. Origin
B. Infinity
C. Origin & Infinity
D. None of the mentioned

Answer: A

On substituting different values in the formula for autocorrelation function will be maximum at the origin.

23. Standard deviation is ______

A. Rms value of dc
B. Rms value or ac
C. Either ac or dc
D. Neither dc nor ac

Answer: B

The standard deviation of a random variable gives the RMS value of an ac component.

24. The average power of white noise is

A. Zero
B. Unity
C. Infinity
D. Between zero and one

Answer: C

The average power of white noise is infinity because its bandwidth is infinite.

25. White noise has _____ mean and ______ variance.

A. Zero and zero
B. Finite and zero
C. Zero and finite
D. One and zero

Answer: C

White noise is a zero-mean function with infinite average power, finite variance, and infinite bandwidth.

26. The process of data conversion along with formatting the data is called ______

A. Formatting
B. Modulation
C. Source coding
D. Amplifying

Answer: C

The process of converting source information to a digital signal and also formatting it is called source coding.

h({});

27. Formatting is the process that includes

A. pulse code modulation
B. Sampling
C. Quantization
D. All of the mentioned

Answer: D

Formatting is the process in which the source information is converted to digital signals using methods like sampling, pulse code modulation, etc.

28. Analog information is converted to digital data using

A. Sampling
B. Quantization
C. Coding
D. All of the mentioned

Answer: D

Textual information, analog information, and digital information undergo different processes before converting to binary or digital data. The method used for converting analog information is the given method.

29. The process that transforms text into binary digits is called _______

A. Binary coding
B. Data coding
C. Character coding
D. Sampling

Answer: C

According to the definition, the process of converting textual data to binary digits is called character coding.

29. For the number of bits, k=1, and number of symbols, M=2 the system is called as

A. Unary
B. Binary
C. Quarternary
D. None of the mentioned

Answer: B

For k number of bits, the number of symbolizes M=2k. For k=1 and M=2 the system is called binary coding.

30. Perform the bit stream partitioning and find the 8-ary waveform for the word ‘THINK’.

A. 1204443464
B. 4643444021
C. 1240443464
D. none of the mentioned