The power we use at home has a frequency of 60Hz. The period of this sine wave can be written as follows:
16.6s
16.6ms
Data not sufficient
0.0166us
A periodic signal has a bandwidth of 20 Hz. The highest frequency is 60 Hz. What is the lowest frequency?
0 Hz
30 Hz
40 Hz
50 Hz
The strength of signals falls off with distance over any transmisison.
Attenuation
Interference
The course COMP 2140 introduces fundamental concepts related to the digital transmission and reception of information.
True
False
Signals can be analog or digital. Analog signals can have an infinite number of values in a range; digital signals can have only a limited number of values.
The values of SNR and SNR(dB) can be calculated as follows:
SNR = (10,000uW / 1 mW) = 10,000
The value of SNR (dB) is 30 dB.
Consider the noiseless channel transmitting a signal with four signal levels . The maximum bit rate can be calculated as:
12,000 Bps
12,000 kbps
1200 bps
None of the above
The loss in a cable is usually defined in decibels per kilometer (dB/km). If the signal at the beginning of a cable with −0.3 dB/km has a power of 2 mW, what is the power of the signal at 5 km in dB?
+1.5 dB
Loss of 1.5 dB
- 1.5 dBm
+3 dB
For any transmission event, the received signal will consist of the transmitted signal modified by the various distortion imposed by the transmission system plus additional unwanted signals that are inserted somewhere between transmission or reception. The latter undesired signals are referred to as:
Noise
There are three causes of impairments which are:
Attentuation
Distortion
Repeater
