Unit 6 - Practice Quiz

1 What is the primary cause of thermal noise in a resistor?

2 The Mean Square Noise Voltage generated by a resistor at temperature (Kelvin) over a bandwidth is given by:

3 Which of the following characteristics best describes thermal noise?

4 If two resistors and are connected in series, what is the effective noise resistance?

5 The standard reference temperature used in noise figure calculations is typically:

6 The Noise Figure () of a network is defined as:

7 The relationship between Noise Figure () and Effective Noise Temperature () is given by:

8 For a cascaded system of two stages with noise figures and and gains and , the Friis formula for the total noise figure is:

9 In a cascaded amplifier system, which stage contributes most significantly to the overall system noise performance?

10 The Noise Equivalent Bandwidth () of a system with transfer function and maximum gain is defined as:

11 Narrow band noise is generally represented in quadrature form as:

12 If a narrow band noise has zero mean, what is the mean value of its quadrature components and ?

13 If the variance of the narrow band noise is , what is the variance of the in-phase component ?

14 The Power Spectral Density (PSD) of the in-phase component is related to the PSD of the narrow band noise by:

15 For a Gaussian narrow band noise, the probability density function (PDF) of the envelope follows a:

16 For a Gaussian narrow band noise, the phase is distributed:

17 If a constant sine wave signal is added to narrow band Gaussian noise, the envelope of the resultant signal follows a:

18 The information content of an event with probability is defined as:

19 The unit of information when the logarithm base is 2 is:

20 Entropy of a discrete random variable represents:

21 The entropy of a source is maximum when the symbol probabilities are:

22 If a source has equiprobable symbols, its entropy is:

23 Information Rate is defined as:

24 Calculate the entropy of a source with two symbols having probabilities and .

25 What is the primary goal of Source Coding (e.g., Huffman)?

26 A code is said to be a Prefix Code (or Instantaneous Code) if:

27 Which of the following coding techniques guarantees the lowest average code length (optimal) for symbol-by-symbol coding?

28 In Huffman coding, high probability symbols are assigned:

29 The efficiency of a source code is given by:

30 The Mutual Information represents:

31 Mutual Information can be expressed in terms of entropy as:

32 If X and Y are independent random variables, their Mutual Information is:

33 The Channel Capacity of a discrete memoryless channel is defined as:

34 For a Binary Symmetric Channel (BSC) with error probability , the capacity is:

35 What is the capacity of a noiseless binary channel?

36 The Shannon-Hartley Law for the capacity of a Gaussian channel with bandwidth and signal-to-noise ratio is:

37 According to the Shannon-Hartley law, if the Bandwidth tends to infinity, the capacity :

38 The Shannon limit for reliable communication states that the minimum required is:

39 The trade-off between Bandwidth and SNR in the Shannon-Hartley law implies that:

40 Kraft's Inequality is a necessary and sufficient condition for the existence of:

41 In Shannon-Fano coding, the first step is to:

42 Redundancy in a code is defined as:

43 The conditional entropy represents:

44 If a channel has a bandwidth of 3000 Hz and an SNR of 30 dB, the approximate capacity is:

45 Which noise source is associated with the discrete nature of charge carriers crossing a barrier?

46 Flicker noise, or 1/f noise, becomes dominant at:

47 The correlation between the in-phase component and the quadrature component of narrow band noise at the same time instant is:

48 If the Noise Figure of an amplifier is 3 dB, what is the output SNR if the input SNR is 20 dB?

49 What is the entropy of a deterministic event (Probability = 1)?

50 The quantity is known as: