Data Communication MCQs with Answers
Practice important Data Communication MCQs with answers and explanations.
Multiple Choice Questions
Q591: What does the decibel (dB) scale measure in relation to signal strength?
- A: Frequency
- B: Loss of energy
- C: Power change
- D: Signal quality
View Answer
C
Q592: If the signal power is reduced to half, the attenuation in dB would be _______?
- A: −3 dB
- B: +3 dB
- C: 0 dB
- D: −10 dB
View Answer
A
Q593: What is the formula to calculate decibels when the power is measured in milliwatts (dBm)?
- A: dBm = 10 log10 Pm
- B: dBm = 10 Pm
- C: dBm = 20 log Pm
- D: dBm = 10 Pm
View Answer
A
Q594: If the power of a signal is reduced by 3 dB, what happens to its strength?
- A: It increases
- B: It remains the same
- C: It is halved
- D: It is doubled
View Answer
C
Q595: In Example 3.26, if the power is reduced to half, the attenuation is calculated as _______?
- A: −3 dB
- B: +3 dB
- C: 0 dB
- D: −10 dB
View Answer
A
Q596: How is the loss of power measured in a transmission medium when using decibels?
- A: dBm = 10 log10 Pm
- B: dB = 10 log10 P
- C: dBm = Pm / 10
- D: dB = Pm * 10
View Answer
B
Q597: In Example 3.29, if the dBm value is −30, what is the power of the signal in milliwatts?
- A: 0.001 mW
- B: 1 mW
- C: 0.0001 mW
- D: 10 mW
View Answer
A
Q598: The relationship between attenuation and amplification in decibels is such that _______.
- A: decibels can be added or subtracted
- B: they cannot be calculated together
- C: amplification is always greater
- D: attenuation and amplification cannot mix
View Answer
A
Q599: In Example 3.27, if the signal's power is increased by 10 times, what happens to the signal?
- A: The power is halved
- B: The power is multiplied by 10
- C: The power remains the same
- D: The power is quadrupled
View Answer
B
Q600: When measuring signal strength in decibels, the calculation of dBm is done by using the formula _______.
- A: dBm = 10 log10 Pm
- B: dBm = 20 log10 P
- C: dBm = Pm * 10
- D: dBm = log10 Pm
View Answer
A