1. Name three types of transmission impairment ?
2. (A) Given the frequencies listed below, calculate the corresponding periods?
1- 20 Hz
2- 150KHz
(B) Given the following periods, calculate the corresponding frequencies.?
1- 20 s
2- 18
(Microseconds)
3. What is the bandwidth of a signal that can be decomposed into five sine waves
with frequencies at 15, 20, 70, 110, and 250 Hz ?
4. A line has a signal-to-noise ratio of 500 and a bandwidth of 5000 KHz. What is
the maximum data rate supported by this line?
5. (A) Name the two major categories of transmission media .
(B)
What is the position of the transmission media in the OSI or the Internet model?
6. Name the advantages of coaxial cable over twisted-pair ?
Multiple choice questions
1- Before data can be transmitted, they must be transformed to ________.
A) Electromagnetic signals
B) Periodic signals
C) Aperiodic signals
D) Low-frequency sine waves
2-As frequency increases, the period ________.
A) Increases
B) Decreases
C) Remains the same
D) Doubles
3-________ is a type of transmission impairment in which the signal loses strength due to the
resistance of the transmission medium.
A) Attenuation
B) Noise
C) Decibel
D) Distortion
4-A signal is measured at two different points. The power is P1 at the first point and P2 at the
second point. The dB is 0. This means ________.
A) P2 is zero
B) P2 equals P1
C) P2 is much larger than P1
D) P2 is much smaller than P1
5-In fiber optics, the signal source is _______ waves.
A) Very low-frequency
B) Radio
C) Light
D) Infrared
6-In an optical fiber, the inner core is _______ the cladding.
A) Less dense than
B) Denser than
C) The same density as
D) Another name for
7-In an environment with many high-voltage devices, the best transmission medium would be
_________.
A) Twisted-pair cable
B) Coaxial cable
C) The atmosphere
D) Optical fiber
8-When a beam of light travels through media of two different densities, if the angle of incidence is greater
than the critical angle, _______ occurs.
A) Refraction
C) Incidence
B) Reflection
D) Criticism