Description : . Is a non-coherent light source foe optical communications system. ∙ a. ILD ∙ b. LED ∙ c. APD ∙ d. PIN Diode
Last Answer : ∙ b. LED
Description : A non-coherent light source for optical communications system. A. PIN Diode B. ILD C. APD D. LED
Last Answer : D. LED
Description : Which of the following is used as an optical transmitter on the Fiber Optical Communications? a. APD b. LSA diode c. PIN diode d. LED
Last Answer : d. LED
Description : Which of the following is used as an optical transmitter on the Fiber Optical Communications? ∙ a. APD ∙ b. LSA diode ∙ c. PIN diode ∙ d. LED
Description : Which of the following is used as an optical receiver in fiber optics communications a. APD b. Tunnel diode c. Laser diode d. LED
Last Answer : a. APD
Description : Which of the following is used as an optical receiver in fiber optics communications ∙ a. APD ∙ b. Tunnel diode ∙ c. Laser diode ∙ d. LED
Description : The most common device used as a light detector in fiber optic communications system. A. LED B. Darlington phototransistor C. APDs D. PIN diode
Last Answer : C. APDs
Description : A pn-junction diode emits light by spontaneous emission ∙ A. LED ∙ B. APD ∙ C. PIN
Last Answer : A. LED
Description : It is the made from semiconductor material such as aluminum-galium-arsenide or gallium-arsenide-phosphide. A. APD B. Injection laser diode C. Light emitting diode D. Positive-intrinsic-negative
Last Answer : C. Light emitting diode
Description : Which optical detector is used when high sensitivity and bandwidth are required? ∙ a. PMT ∙ b. APD ∙ c. PIN ∙ d. Phototransistor
Last Answer : a. PMT
Description : One of the following is not a solid-state optical detector ∙ a. APD ∙ b. PIN ∙ c. PMT ∙ d. Phototransistors
Last Answer : . PMT
Description : Laser light is ______ emission. a. Coherent b. Stimulated c. Spontaneous d. Coherent and stimulated
Last Answer : d. Coherent and stimulated
Description : Circuit used to amplify the optical signal in fiber optics communications links. A. Attenuator B. Optical repeater C. Optical amplifier D. Generator
Last Answer : B. Optical repeater
Description : What optical source radiates light uniformly in all directions? A. Isotropic source B. Lambertian source C. Voltage source D. Ideal source
Last Answer : B. Lambertian source
Description : A coherent binary phase shift keyed BPSK transmitter operates at a bit rate of 20 Mbps with a carrier to noise ratio C/N of 8.8dB. Find Eb/No. A. 73 dB B. 62.4 dB C. 81.8 dB D. 8.8 dB
Last Answer : D. 8.8 dB
Description : Noise always affects the signal in a communications systems at the ________. A. transmitter B. channel C. information source D. destination
Last Answer : B. channel
Description : The main benefit of light-wave communications over microwaves or any other communications media is a. Lower cost b. Better security c. Wider bandwidth d. Freedom from interference
Last Answer : c. Wider bandwidth
Description : Which of the following is the fastest light sensor? ∙ A. PIN photodiode ∙ B. Photovoltaic diode ∙ C. Photodiode ∙ D. Avalanche photodiode
Last Answer : Avalanche photodiode
Last Answer : D. Avalanche photodiode
Description : Which of the following is the fastest light sensor ∙ a. PIN photodiode ∙ b. Photovoltaic diode ∙ c. Phototransistor ∙ d. Avalanche photodiode
Last Answer : ∙ d. Avalanche photodiode
Description : Which of the following is NOT a common light detector ∙ a. PIN photodiode ∙ b. Photovoltaic diode ∙ c. Photodiode ∙ d. Avalanche photodiode
Last Answer : ∙ b. Photovoltaic diode
Description : In a PIN diode, leakage current in the absence of light is called: a. baseline current b. zero-point current c. dark current d. E-H current
Last Answer : c. dark current
Description : Which of the following contributes to the broadening of laser emission bandwidth? a. Doppler shift of moving atoms and molecules b. Amplification within the laser medium c. Coherence of the laser light d. Optical pumping of the laser transition
Last Answer : a. Doppler shift of moving atoms and molecules
Description : What is a specific path the light takes in an optical fiber corresponding to a certain angle and number of reflection a. Mode b. Grade c. Numerical Aperture d. Dispersion
Last Answer : a. Mode
Description : Is the different angle of entry of light into an optical fiber when the diameter of the core is many times the wavelength of the light transmitted. a. Acceptance angle b. Modes c. Sensors d. Aperture
Last Answer : b. Modes
Description : What law does a light traveling in air optical fiber follow? A. Millman B. Snell’s C. Maxwell D. Huygen
Last Answer : B. Snell’s
Description : A device that reduces the intensity of light in fiber optics communication systems. A. Reducer B. Quality factor C. Optical attenuator D. Compressor
Last Answer : C. Optical attenuator
Description : The different angles of entry of light into an optical fiber when the diameter of the core is many times the wavelength of the light transmitter is known as ________. A. refraction B. sensor C. mode D. emitter
Last Answer : C. mode
Description : What is the free space attenuation of a satellite communications system operating at 36,000 km above the earth at 5.0 GHz? A. 198 dB B. 202 dB C. 142 dB D. 138 dB
Last Answer : A. 198 dB
Description : The key electronic component in a communications satellite is the A. telemetry equipment B. on-board computer C. command and control system D. transponder
Last Answer : D. transponder
Description : An automated ship-to-shore distress alerting system using satellites and advanced terrestrial communications systems. A. GPS B. Iridium system C. INMARSAT D. GMDSS
Last Answer : D. GMDSS
Description : What term is used to describe a spread spectrum communications system in which a very fast binary bit stream is used to shift the phase of an RF carrier? A. Frequency hopping B. Direct sequence C. Binary phase-shift keying D. Phase compandored spread spectrum
Last Answer : B. Direct sequence
Description : What is the term used to describe a spread spectrum communications system where the center frequency if a conventional carrier is altered many time per second in accordance with a pseudo ... hopping B. Direct sequence C. Time-domain frequency modulation D. Frequency compandored spread spectrum
Last Answer : A. Frequency hopping
Description : One of the first satellite system catering personal based communications services scheduled for operation. A. Iridium system B. Plutonium system C. Indium system D. Gallium system
Last Answer : A. Iridium system
Description : A microwave communications system space loss calculation formula is A. 92.4 + 10 log f +20 log d B. 94.2 + 10 log f +20 log d C. 92.4 + 20 log f +20 log d D. 94.2 + 20 log f +20 log d
Last Answer : C. 92.4 + 20 log f +20 log d
Description : RS-232, RS-449, RS-530, V, 24 and X.21 are examples of ____________. A. standards for interfaces between modems and transmission facilities B. standards for various types of ... for interfaces between terminals and modems D. standards for end to end performance of data communications system
Last Answer : C. standards for interfaces between terminals and modems
Description : The correctness and accuracy of the transmitted message content is A. verified by the modem B. communications system C. determined by the sender and receiver D. ensured by use of digital technique
Last Answer : C. determined by the sender and receiver
Description : What is the main purpose of a communications system? A. None of these B. To have a frequency assignment C. For modulation D. To provide an acceptable replica of the information at the destination
Last Answer : D. To provide an acceptable replica of the information at the destination
Description : ECE Board Exam March 1996 One type of pulse communications system uses pulse that appear as a group, and which vary in number according to the loudness of the voice. This type of ... A. pulse duration modulation B. pulse amplitude modulation C. pulse code modulation D. pulse position modulation
Last Answer : A. pulse duration modulation
Description : ECE Board Exam March 1996 It is a spacecraft placed in orbit around the earth carrying onboard microwave receiver and transmitting equipments. A. Fiber optic equipment B. Communications satellite C. Wireless radio system D. Coaxial cable syste
Last Answer : B. Communications satellite
Description : Television signals are converted into light signals by------? A. Optical fiber B. Transistor C. Decoder D. Photo diode (Answer) E. None of these
Last Answer : D. Photo diode (Answer)
Description : How much power (roughly) a light emitting diode can couple into an optical fiber? a. 100 microwatts b. 440 microwatts c. 100 picowatts d. 10 miliwatts
Last Answer : 100 microwatts
Description : The term responsivity as it applies to a light detector is best described as ∙ A. the time required for the signal to go from 10 to 90 percent of maximum amplitude ∙ B. the ratio of the diode ... . the ratio of the input power to output power ∙ D. the ratio of output current to input current
Last Answer : the ratio of the diode output current to the input optical power
Description : If I am a 13 year ild boy who doesnt have much arm hair to begin with but its still noticeable and i accidentally shave of a small part of hair on my arm will it grow back differently?
Last Answer : No it won't change. Don't worry about having hair at your age. In 6 months you won't know your body.
Description : Type of lasers that use solid, cylindrical crystals such as ruby ∙ A. solid lasers ∙ B. ILD ∙ C. gas lasers ∙ D. liquid lasers
Last Answer : ∙ A. solid lasers
Description : What is the spectral width of an ILD? ∙ A. 0.1 nm to 1 nm ∙ B. 2 nm to 5 nm ∙ C. 1 nm to 3 nm ∙ D. 3 nm to 4 nm
Last Answer : C. 1 nm to 3 nm
Description : Which does not use vertical polarization antenna? A. AM Broadcasting B. FM Broadcasting C. Mobile Communications D. Satellite Communications
Last Answer : B. FM Broadcasting
Description : Which of the following is the most common application of satellite? A. Surveillance B. Military application C. Communications D. Newscasting
Last Answer : C. Communications
Description : The satellite communications channels in a transponder are defined by the A. LNA B. bandpass filter C. mixer D. input signals
Last Answer : B. bandpass filter
Description : The satellite subsystem that monitors and controls the satellite is the A. propulsion subsystem B. power subsystem C. communications subsystem D. telemetry, tracking, and command subsystem
Last Answer : D. telemetry, tracking, and command subsystem