This is the Section 1 Module 11 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 1 Module 11
|What technique is employed by the transmitter to avoid accidental flags?
|What refers to the emphasizing of low level signals and compressing of high level signals?
|Why “downtilt” is used in cellular base stations?
|Because it can be used to reduce the range of a base station to reduce interference
|In TV system, if the 3.58 MHz C amplifier in the receiver does not operate the result will be____
|What filter may be connected between CB transmitter and its antenna?
|Low Pass Filter
|How is fiber grating produced?
|By illuminating the fiver with ultraviolet light
|What types of microphone have high Z output?
|Crystal, electret and condenser
|How is a packaged single button microphone cleared
|What are pulses that retain their shapes as they pass through optical fibers?
|What is the measure of the sensitivity o the detector to light?
|What refers to the series of tones that sound good when used
|A TV receiver design that uses mixing between the picture and sound carriers to generate the sound IF. What do you call this sound?
|What microphones are predominantly used in Aviation services
|In TV, what is the hue of a 90 degree leading sync burst
|A 100 Mbps LAN signaling standard intended for use in fiber optics but also used with coaxial cables
|Fiber Distribution Data Interference (FDDI)
|In IMT 2000, what does 2000 refer to?
|Both the implementing date (year 2000) and operating frequency (2000 MHz)
|A system that allows users to access documents from widely separated sources on the internet using a common interface
|World Wide Web
|What do you call the perceptible sound repetition?
|What is the reason why point contact and Schottky or hot carrier diodes are widely used as mixers in microwave equipment
|They have low capacitance and inductance
|What do you call the area that lies between the outer limit of the ground wave range and the inner edge of energy returned form the ionosphere?
|What principle is employed in cellular telephony to allow simultaneous transmission and reception without the need to push to talk?
|What harmonics are in a square wave
|Which of the following is not a bit oriented protocol?
|The rbe dose is expressed in __________?
|Rems (roentgen equivalent man) or rebs (roentgen equivalent biological)
|In TV, special effects and production switching are done by the
|Special Effects Groups (SEG)
|What is the primary application of fiber optic communication?
|Long-distance telephone system
|A point on a line between the earth’s center and an observer located farther from the earth’s center than the point is called
|What is the noise reduction effect that occurs with strong FM signals
|What junction device can operate as an oscillator or amplifier by means of avalanche breakdown?
|Which of the following is not an acoustical signal defect to be avoided in acoustical signals?
|What waveguide-like device that acts like a high Q parallel resonant circuit?
|What modulation method is used by GPRS system
|What helps protect fivers against degradation caused by moisture
|For an angle of incidence equal to the critical angle, the light will be refracted
|Along the normal
|If a rocket contains more than one satellite, the smaller satellite that will be launched after the main satellite is called
|What do you call an interval which … integer ratio or a whole fraction ratio?
|What is the hue color sync phase?
|What is any tone produced by a sound source in addition to the fundamental tone
|In communications system, the total system noise in the absence of information transmission is called
|The average voltage value of the 3.58 MHz modulated chrominance signal in TV receiver is___
|The brightness of the color
|In TV system, which signal has information for 1.3 MHZ bandwidth?
|A lens has an 8-cm focal length and a 4-cm diameter. What is its F rating?
|How much more feed point impedance does a folded dipole have than a normal dipole?
|The electronic serial number (ESN) assigned to the mobile phone at the factory consists of _____
|How many scanning lines does a standard NTSC have?
|Solid state neodymium can generate high power at
|1.3 micro seconds
|A radar mile is the time required for a radar pulse to travel 1 mile to an object and return to the receiver. 1 radar nautical mile is equivalent to ____ microseconds
|12.4 micro seconds
|How long does a repeater transmit a mobile signal drop out?
|What is the orbital period of each GPS constellation?
|What loudness level in which permanent damage to hearing is possible?
|What is the minimum ratio of visual signal level to system noise, and of visual level to any undesired co-channel TV signal operating on proper offset performance?
|In CATV, what is the noise figure for mid, high and super band channels?
|6 dB or better
|In CATV system, what is the noise figure for sub and 10- band channels?
|5 dB or better
|What is the maximum height above average terrain for a class B FM station?
|What is the maximum recommended cable length for an RS 232C cable
|LEO satellites orbit the earth at an altitude less than how many kilometers?
|What is the end impedance of a half wave dipole
|What is the typical loudness level of a watch ticking
|In FM broadcasting, what is the highest required modulating frequency?
|What is the maximum deviation of cellular radios that use FM?
|What is the frequency used to signal handoffs to another cell and the termination of the cell in cellular communications?
|At what frequency does magnetron microwave oven operates?
|How wide are GSM channels
|What is the frequency of middle C?
|In general, what frequency range does a troposcatter wave propagation will be effective?
|350 MHz to 10 GHz
|What would be the bandwidth of … filter for voice and SSB
|What is the conduction angle of Class C amplifier?
|Less than 180 degrees
|What is the letter number designation of AM voice or music emission?
|What protocol is very poplar system for defining and switching data packets on computer networks?
|When was the first commercial system operated?
|October 13, 1983
|What class of mobile phone has a maximum power level specified as effective radiated power (ERP) of -2 dBW (600 mW)
|Class 3 (portable phone)
|What class of mobile phone has a maximum power level specified as effective radiated power (ERP) of 1.68W
|What class of mobile phone has a maximum power level specified as effective radiated power (ERP) of 3W