RCDD TEST QUESTIONS WITH VERIFIED SOLUTIONS 2023

If the input signal power to a communication system is 1 W and the output power is 1 mW, the system attenuation is: A. 3 dB B. 20 dB C. 30 dB D. 40 dB E. 1000 dB C. 30 dB The signal at the input to a balanced twisted pair cable is 10 mW. The cable is 1000 feet long and has an attenuation of 1 dB per 100 feet. This cable is connected to the input of a receiver. The noise level at the input to the receiver is 1 microwatt. What is the signal-to- noise ratio (SNR) (dB) at the receiver input? A. 10 dB B. 30 dB C. 40 dB D. 60 dB E. 100 dB B. 30 dB A SONET OC-1 channel can carry 672 voice signals and has a data rate of 51.84 Mbps. ASONET OC-48 channel can carry 32,256 voice channels. What MINIMUM data rate is required for the OC-48 channel? A. 155 Mbps B. 622 Mbps C. 2.5 Gbps D. 5 Gbps E. 10 Gbps C. 2.5 Gbps All of the following are nominal wavelengths for laser light sources EXCEPT: A. 700 nm B. 850 nm C. 1300 nm D. 1310 nm E. 1550 nm A. 700 nm A video camera has a coaxial cable output. The video signal is to be distributed to devices that have balanced twisted pair inputs. The transition between these two different transmission media can be accomplished by using a: A. Balun B. Converter C. Modulator D. Cross connect E. Transceiver A. Balun The public telephone system is an example of a __________ system. A. Simplex B. Half-duplex C. Full-duplex D. Purely analog E. Purely digital C. Full-duplex Wave division multiplexing (WDM) is most similar to: A. Amplitude modulation B. Frequency modulation C. Time division multiplexing D. Frequency division multiplexing E. Carrier sense multiple access with collision detection (CSMA/CD) D. Frequency division multiplexing You must place CAT6 cable above a factory floor with automated welding machines and hammer forges. Of the following, what type of shielding would be most effective? A. Multi-layer braid B. Foil and braid C. Solid metallic conduit D. Flex metallic conduit E. Sch. 40 PVC conduit C. Solid metallic conduit You must place a cable between 2 equipment locations with separate grounds having a potential difference between them of 2.1 V rms. Which one of the following cables should NOT be used? A. Multimode B. Singlemode C. UTP D. STP D. STP Two sinusoidal signals have the same amplitude (A) and the same frequency (f). They differ in phase by 180 degrees. If these two signals are added together, the result is a sinusoidal signal having an amplitude of: A. Zero B. 0.707A and a frequency of f C. A and a frequency of 2f D. 2A and a frequency of f E. 2A and a frequency of 2f A. Zero Composite conductors, although not generally recommended, may be used in special circumstances because they provide all of the following advantages EXCEPT: A. Have good digital transmission characteristics B. Lightweight C. Inexpensive D. Easy to produce E. Easily embedded into other materials A. Have good digital transmission characteristics Which is an advantage of stranded conductors over solid conductors? A. Less costly B. Simpler terminations C. Better high frequency performance D. More flexible D. More flexible The conversion of an analog speech signal to a pulse code modulation (PCM) digital signal involves all of the following steps EXCEPT: A. Low pass filtering B. Periodic sampling C. Quantizing D. Companding E. Amplitude modulation E. Amplitude modulation Assume that the optical power transmitted by a 62.5/125 multimode fiber is distributed uniformly across its core. If this fiber is perfectly coupled (i.e., the two fibers are aligned and abutted) to a 50/125 fiber, what is the percent of power that is lost? A. 0 percent B. 36 percent C. 50 percent D. 80 percent E. 100 percent B. 36 percent Which of the following correctly lists the lowest frequency band to the highest frequency band? A. MF, HF, VHF, UHF B. UHF, VHF, HF, MF C. HF, MF, UHF, VHF D. VHF, UHF, MF, HF E. HF, MF, UHF, VHF A. MF, HF, VHF, UHF Time division multiplexing (TDM) systems are designed to transport ________ between end point systems. A. Only analog signals B. Only digital signals C. A mix of both analog and digital signals D. Both analog and digital signals, but only one type at a time B. Only digital signals A reasonable approximation for the signal speed in 100 ohm balanced twisted pair cable is__________, where c is the velocity of light in free space. A. 0.2 c B. 0.4 c C. 0.6 c D. 08 c E. 0.9 c C. 0.6 c Which characteristic is an advantage of copper based media over optical fiber cable? A. Weight B. Corrosion resistance C. Ability to handle analog signals D. Susceptibility to EMI E. Very high data rates C. Ability to handle analog signals Which electrical characteristic is displayed with the correct preferred value? A. Dielectric constant - high value B. Dielectric strength - high value C. Dissipation factor - low value D. Insulation resistance - high value A. Dielectric constant - high value Optical transmitters are typically one of the following types EXCEPT: A. Light-emitting diode (LED) B. Short wavelength laser compact disc (CD) C. Vertical cavity surface emitting laser (VCEL) D. Laser diode (LD) E. Overfilled launch (OFL) E. Overfilled launch (OFL) You are placing Category 6 unshielded twisted-pair (UTP) in cable tray down a hallway past the elevator mechanical room. What action should you take to avoid effects of electromagnetic interference (EMI)? A. Provide a minimum separation of 1194 mm (47 in) B. Provide a minimum separation of 2060 mm (81 in) C. Require the architect to install metallic foil shielding on the mechanical room walls D. Provide RMC/IMC (rigid metallic conduit/intermediate metal conduit) through all areas within 4.6 m (15 ft) of the mechanical room A. Provide a minimum separation of 1194 mm (47 in) You have discovered a common mode current on the metallic cable sheaths of your building riser cables. What is the MOST likely cause for you to investigate? A. Lack of cable protection B. Two separate and distinct ground references C. Improper secondary protection D. Improper physical protection of cable E. Improper placement and/or termination of cables B. Two separate and distinct ground references What is the recommended MINIMUM separation of unshielded twisted-pair (UTP) cables from fluorescent light fixtures? A. 77 mm (3 in) B. 30 mm (5.12 in) C. 203 mm (8 in) D. 324 mm (12.75 in) E. 483 mm (19 in) B. 30 mm (5.12 in) You are required by architectural design to place UTP cables in the same space as unshielded power lines. How should you proceed with the placement of your cables? A. Require the architect/electrical engineer to place shielding in the space before your UTP is placed. B. You should provide a minimum separation of 610 mm (24 in). C. You should provide a minimum separation of 229 mm (9 in). D. You should provide a minimum of two 101 mm (4 in) RMC. B. You should provide a minimum separation of 610 mm (24 in). Which of the following is NOT a form of signal coupling between two (2) circuits? A. Conductive B. Inductive C. Reactive D. Capacitive E. Electromagnetic C. Reactive A common mode (CM) signal can be converted to a differential mode (DM) signal as a result of a(n): A. Unbalanced circuit B. Grounded circuit C. Poorly timed signal D. Improper dielectric material A. Unbalanced circuit The electromagnetic spectrum of visible light lies in the ___________ frequency range of the spectrum. A. 1 GHz B. 100 GHz C. 10 THz D. 1 PHz E. 100 PHz D. 1 PHz The potential for ______ occurs when devices or systems share a common electromagnetic environment and their operational frequencies overlap. A. Electromagnetic interference (EMI) B. (EMC) C. Radio frequency interference (RFI) D. Fast transients E. Electrostatic discharge (ESD) A. Electromagnetic interference (EMI) Which of the following is an undesirable electromagnetic effect on a device(s)? A. (EMC) B. Electromagnetic interference (EMI) C. Radio frequency interference (RFI) D. Fast transients E. Electrostatic discharge (ESD) B. Electromagnetic interference (EMI) During a site survey you notice that several CRT displays in the vicinity of the engineering copy center have sporadic visual distortion. What is the MOST likely cause? A. Electromagnetic interference (EMI) B. Radio frequency interference (RFI) C. (EMC) D. Fast transients E. Electromagnetic discharge (ESD) A. Electromagnetic interference (EMI) The ability of a device to withstand electromagnetic disturbances from another device is: A. Electromagnetic interference (EMI) B. Radio Frequency Interference (RFI) C. (EMC) D. Fast transients E. Electrostatic Discharge (ESD) C. (EMC) Which of the following is NOT a source of electromagnetic interference (EMI)? A. Copiers - B. Transformers - C. Incandescent lights - D. Fluorescent lights - E. Electrical power supply cable C. Incandescent lights - If looking to specify an optical fiber backbone within a building going 275 m (902 ft) between the equipment room (ER) and the telecommunications room (TR), what type of fiber should be specified to support a 10 GB ethernet application? A. OM1 B. 50 micron multimode C. 50 micron laser optimized multimode D. 62.5 micron multimode C. 50 micron laser optimized multimode