This is the Section 5 Module 4 of the compiled Communications Coaching Materials taken from various sources including but not limited to past Board Examination Questions in Electronic System and Technologies (EST), Communications Books, Journals and other Communications References. This particular Coaching Notes in Communications Engineering has random Questions and Answers in random topics. Make sure to familiarize each questions to increase the chance of passing the ECE Board Exam.
Communications Engineering Coaching: Section 5 Module 4
To connect coaxial to a parallel wire
Gain of an isotropic antenna
What is the term used for an equivalent resistance that would
dissipate the same amount?
Resulting from obstruction losses
log normal fading
Radiation pattern of a discone
Band of light waves
Which of the following antennas receives signals from all
direction in horizontal plane?
vertical marconni antenna
What happens to beamwidth?
the beamwdith increases as the gain is increased
3:00 PM is a standard time
What is the total resistance of an antenna system?
radiation resistance + ohmic resistance
In which crosstalk dBx ????????
How can be antenna efficiency ????????????
by installing a good ground radar system
What optical source radiates light in all directions?
What is the protocol that is used in transferring files?
What signal to noise ratio for satisfactory TV?
cable consists of twisted pairs of conductors, each separately
30 -53 KHz
signal to noise ratio required for satisfactory TV reception
Start of test for BISYNC
Short bit sequence 128 bits
rules and description binary
affected by the distance
information about satellite send to earth
if away from source
measures virtual height of ionosphere
sound travels fastest at
What is the GPS ???????????????
100meters ,95% of the time
According to the nyquist theory the sampling rate is _____
twice the highest frequency
It consists of a number of dipoles
Line of sight mode of propagation
space or direct wave
What causes a maximum frequency Vary ???????????????
the amount of radiation received from the sun
The low power short range wireless technology
What is the insertion loss of connector splices?
Which of the following frequency is normally used in safety
What determine the ability of a radar?
What is the meaning of velocity factor?
the velocity of the wave divided by the velocity of light
For T carrier system, T3 has a bit rate of _____
A half wave antenna operates at very high efficiency ____
because the conductor resistance is low compared to the
Process of a signing pcm codes absolute magnitudes
What distortion is does not cause by TL characteristics?
spacing bias distortion
After IF stages
Spot in the visible surface of the sun
What is the number pins of R232 C?
What for the ratio of radiation resistance to the total
What is the reference tone level for dbm?
What is the quantization signal to noise ratio if an 8 bit PCM
Which is space diversity?
two or more antennas operating in the same frequency
The lowest layer in the ionosphere
What causes a interference?
poor front end selectivity
Cross modulation in the receiver is eliminated at the ____
Which of the ff antennas require good grounding?
In an FM receiver which circuit is used amplitude variations
What deviation is measured for an angle?
What is the minimum propagation delay for stationary
A unique character is transmitted at the beginning of each
tv receiver that separates sound
the TACAN is a nav aid providing ___
bearing and distance indication
What is the spectrum of FM signal?
What is the emission designation of single sound reduced
the mid-range frequency range of sound is
the standard deviation of in transmission loss should not
modem are required to connect
the telephone network will pass DC
What kind of impedance 1/8 wavelength TL present to a
an inducting reactance
What noise is short duration?
What is the channel spacing of ???????????
How is antenna efficiency computed?
efficiency = radiation resistance divided
resistance X 100%
an absorption loss caused by valence electron
is a device in data transmission to interface a data to
What is the most commonly used IF of radar receivers?
layer that exist only during daylight
Frequency spectrum ??????
Attenuates signals that passes frequency below
zone of silence
Station in the mobile service not intended to use
The letter number designation B8E
What is the typical separation between two conductors?
0.635 – 15cm
Which of the following pulse modulation is ???????????
Connecting an antenna electrically add a
An ITU-T that deals with the telephone circuits
Cause some frequency to be delayed with respect to other
Occurs when a microwave beam is at point
The input signal of a TWT
cathode end of a helix
An equipment used to measure SWR
Is a standard where mobile phone can access to specially
tailored internet websites
In what region of the world is sporadic E
A radio communication service used for aeronautical safety
aeronautical fixed service
What kind of impedance ¼ wavelength?
a very low impedance
Propagation mode microwave
How far is the visual carrier of monochrome TV channel?
A helical antenna is used for satellite tracking
What is ascending pass for a LEO?
from south to north
A properly connected Transmission Line has a ____
SWR as near as 1:1 as possible
What is the primary advantage of ?????????????
no transmitted power is wasted in the carrier
What device is used in diverting electromagnetic?
A type of underground antenna
A type of array which contains of 1 half wave dipole, 1
reflector and 1 director
What happens to a path wave as it is shorted through the use
of loading coils?
What do you call the incident light that have different
What is the standard test tone used for audio measurements?
Capture effect is most pronounced in what type of emission
What is the GPRS uplink rate?
What is the advantage of Doherty linear?
Frequency of VCR control signal
A type of microphone which has a permanent magnet
Block calls delays
On a telephone system, the loop is open during ___
on hook condition
A telephone line connecting two central offices
The SPL in dB of an auditorium with contemporary music is ___