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WorksheetsWCM - Chpt2
Total questions: 13
Worksheet time: 7mins
Q1) Define the following terms:
Frequency
The speed at which a wave travels through a medium
The distance between two consecutive peaks of a wave
The maximum height of a wave from its rest position.
Frequency of a signal is the number of complete cycles per second.
Define the following terms: Wavelength
The number of cycles of a wave that pass a fixed point in one second.
The distance travelled by a wave during the time of one cycle
The speed at which a wave travels through a medium.
The maximum height of a wave from its rest position
Define the following terms: Period
The number of cycles of a wave that pass a fixed point in one second.
The maximum height of a wave from its rest position.
Period of a signal is the time taken to complete one cycle.
The distance between two consecutive peaks of a wave.
The wavelength of a radio frequency signal is 3m. Determine its:
•Frequency
•Period
f = 100MHz
T = 0.01μs
f = 10MHz
T = 0.01μs
f = 100MHz
T = 0.1μs
f = 100KHz
T = 0.01μs
A radio signal has a frequency of 88MHz. Determine its
(a) Wavelength
(b) Period
λ = 3.48m
T = 11.8ns
λ = 3.41m
T = 11.4ns
λ = 3.41m
T = 11.4μs
λ = 3.41n
T = 11.4μs
State four common types of ‘Line Encoding’
Amplitude Modulation, Frequency Modulation, Phase Modulation, Pulse Width Modulation
Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), Code Division Multiplexing (CDM), Space Division Multiplexing (SDM)
Pulse Amplitude Modulation (PAM), Quadrature Amplitude Modulation (QAM), Frequency Shift Keying (FSK), Phase Shift Keying (PSK)
Unipolar Encoding, Polar Encoding, Bipolar Encoding, Manchester Encoding
Define ‘Baud Rate’
The maximum number of bits transmitted per second.
The number of signal units per second that are required to represent those bits.
The number of cycles of a wave that pass a fixed point in one second.
The time it takes for one complete cycle of a wave to pass a fixed point.
An Analogue Signals carries 8 bits in each signal element. If 1000 signal elements are sent per second, determine its ‘Baud Rate’ and ‘Bit Rate’.
Baud Rate = 1000 bauds per second
Bit Rate = 8000bps
Baud Rate = 10000 bauds per second
Bit Rate = 80000bps
Baud Rate = 100 bauds per second
Bit Rate = 800bps
Baud Rate = 10 bauds per second
Bit Rate = 80bps
The ‘Bit Rate’ of a signal is 2000bps. If 500 signal elements are sent per second, calculate the number of bits in each signal element.
Number of Bits per Signal Element= 4 bits
Number of Bits per Signal Element= 8 bits
Number of Bits per Signal Element= 16 bits
Number of Bits per Signal Element= 32 bits
Determine the ‘Baud Rate’ of a data communication network that has a data transmission rate of 64kbps with each signal element carrying 8 bits.
Baud rate = 32k baud per sec
Baud rate = 4k baud per sec
Baud rate = 8k baud per sec
Baud rate = 16k baud per sec
State the three steps involved in ‘Pulse Code Modulation’ (PCM).
Sampling, Quantization, Encoding
Sampling, Modulation, Demodulation
Quantization, Encoding, Decoding
Compression, Transmission, Decompression
Explain ‘Quantization Noise’ in a PCM system.
The noise generated by the transmission medium during the signal transmission.
The interference caused by overlapping signals in a communication channel.
Distortion by the difference between sampling point amplitudes and quantum levels.
The reduction in signal quality due to the limited bandwidth of the transmission channel.
How can ‘Quantization Noise’ be reduced in a PCM system?
Increasing the sampling rate
Reducing the step size
Decreasing the transmission power
Reducing the bandwidth of the transmission channel
