Practice

23. In a closed parallel circuit: a. the total current flow will be less than the sum of the individual loop currents. b. the total current flow will equal the sum of the individual loop currents. c. the total current flow will exceed the sum of the individual loop currents. d. None of the above

The correct answer is "b." It is a fundamental law of electrical theory that, in a closed parallel circuit, the total current flow is equal to the sum of the individual loop currents.

24. Assuming everything else is held constant, Ohm's law states that, as the current level of an electrical circuit increases: a. its voltage decreases. b. its resistance decreases. c. its inductance decreases. d. its capacitance decreases

The correct answer is "b." Ohm's law states that, for any circuit, the electric current is directly proportional to the voltage and is inversely proportional to the resistance. Ohm's law does not involve inductance or capacitance.

2. In residential areas, buried services are normally placed at depths of _____, unless a local zoning ordinance specifies otherwise. a. 6-12 inches b. 12-18 inches c. 18-24 inches d. 24-36 inches

The correct answer is "b." Telecommunications industry standards in residential areas specify that buried lines are to be placed at a depth of 12-18 inches, unless a local zoning ordinance supersedes industry standards.

18. When using an Ohmmeter to measure a properly functioning component: a. a short will be measured across a ceramic capacitor. b. an open will be measured across a mylar capacitor. c. an open will be measured across a power transformer primary. d. an open will be measured across loud speaker terminals.

The correct answer is "b." The Ohmmeter reading of properly functioning ceramic and mylar capacitors will indicate an open circuit. The Ohmmeter reading for both power transformer primaries and loud speaker terminals will show very low resistance, which does not indicate an open circuit.

27. A temporary bond is used to: a. temporarily fix a ground in a telephone circuit. b. bond metallic fixtures while working aloft. c. ground a telephone circuit. d. remove excessive noise from a telephone line.

The correct answer is "b." The function of a B-temporary bond is to bond metallic fixtures to an earth ground. This is done to protect workers who might come into contact with potentially dangerous voltages while working in the vicinity of such fixtures. B-temporary bonds are used only on metallic fixtures. Response options "a," "c," and "d" all refer to communication circuits

4. Which of the following statements about installation of protectors is true? a. Ground wires must not be spliced. b. Gas tube protectors should be mounted on the pole to protect the drop line. c. Wire with a gauge number of 22 or higher should be used to ground the protector. d. Protectors used with aerial drops should be mounted within 6 inches of where the drop attaches to a building.

The correct answer is "a." A good ground is necessary for a protector to function correctly. A spliced ground wire can, however, defeat the purpose of protectors. This is because exposed splices tend to degrade over time due to corrosion, resulting in failure of the ground. This failure occurs because corrosion causes resistance to form, which means the current will flow along a less resistant path than the one to the ground wire.

7. In a buried wire environment, the choice of whether to take a plowing or trenching approach to cable installation should be made during the: a. pre-survey. b. inspection of tools. c. notification of Central Office. d. installation.

The correct answer is "a." A pre-survey is always done before any cable installation so that technicians know they have the proper materials (both type and amount). Tool inspection does not factor into the decision regarding plowing versus trenching. Once an approach has been selected, only then can the correct tools be chosen. The Central Office has nothing to do with how a wire is buried. And, of course, the choice should not be made during installation of the cable, since the technician may not have all of the appropriate tools and equipment. Moreover, if the choice were made during installation, the field drawings would have to be updated.

19. A diode is used to: a. regulate voltage b. amplify current c. filter audio d. switch circuits

The correct answer is "a." Diodes are widely used to regulate voltage across a circuit. A diode conducts once the voltage reaches the diode's reverse breakdown voltage (assuming it is connected in parallel with a variable voltage source so that it is reverse biased). The diode then maintains the voltage at that value.

6. Load coils: a. must be removed for digital circuits to function b. must be used on T-1 lines c. must be used on ISDN BRI lines d. Both b and c

The correct answer is "a." Load coils (impedance matching transformers) are placed on POTS lines that exceed 6,000 feet. Load coils enhance the quality of analog voice signals by limiting the upper portion of the frequency spectrum, which is required by digital signals. Consequently, they interfere with the functioning of digital circuits.

22. What is the total current flow reading on the ammeter in this circuit? a. 0 amps b. 4.8 amps c. 6.4 amps d. 9.6 amps

The correct answer is "a." Since the switch is open, no current can flow and the ammeter measuring the total current flow in the circuit will read 0 amps. It is important to study a complete circuit before beginning to calculate voltages and current flows. If the switch were closed, Ohm's law could be used to calculate an answer.

25. Which meter will be used when measuring the signal-to-noise ratio on a DSL circuit? a. Subscriber Loop Analyzer (e.g., 9651) b. OTDR c. T-BERD d. Cable Hound

The correct answer is "a." The subscriber loop analyzer is designed specifically to test the ratio of signal-to-noise on a DSL circuit. It does so using various test functions built into the equipment that compare the level of the signal to the level of the ambient noise on the circuit.

8. Which of the following is a disadvantage of standard twisted wire relative to coaxial cable? a. It is more susceptible to electrical interference (noise). b. It is very expensive. c. It is more difficult to work with. d. It takes longer to splice.

The correct answer is "a." Twisted wire does not have a shield around it to block electrical interference, whereas coaxial cable does. As such, twisted wire is more susceptible to electrical interference. Twisted wire is less expensive to manufacture than coaxial cable because it is less complex and uses less material per foot. Twisted wire is easier to work with than coaxial cable because the braided shield that makes up coaxial cable (whether it is made of copper or another metal) is more difficult to connect or bond to than twisted wire. Finally, splicing coaxial cable takes longer than splicing twisted wire because splicing coaxial cable requires the shield around the cable to be completely bonded to the splice. This adds complexity to the splicing process, which consequently takes longer to complete.

28. If an electrical fault develops on an electrical fixture while it is connected with a B-temporary bond to a direct path to ground, the B-bond will: a. beep. b. emit smoke. c. light up. d. break.

The correct answer is "b." B-temporary bonds are designed to emit harmless smoke whenever an electrical fault occurs. This is done to alert workers to hazards so they can cease work until the fault can be resolved and it is safe to continue.

26. What type of circuit is depicted in the figure below? a. Series circuit b. Parallel circuit c. Solid state circuit d. Resonant circuit

The correct answer is "b." In the circuit above, all of the elements connect to the same two wires from the battery. The symbol used for the elements is that of a resistor. Since there are no capacitors or inductors shown, it cannot be a resonant circuit. Since there are no solid-state devices such as diodes or transistors, it cannot be a solid-state circuit. The resistors are arranged in parallel (that is, side-by-side with all elements connecting to the same upper and lower wires), not in series.

14. What four factors affect the resistance of a conductor? a. Length, weight, height, and size b. Temperature, length, size, and type of material c. Ground, weight, type of material, and length d. Voltage, size, length, and temperature

The correct answer is "b." The resistance of a conductor: (a) decreases as the temperature decreases, (b) increases as the length of the conductor increases, and (c) decreases as the size (cross sectional area) of the conductor increases. Some types of materials are better conductors than others and, as such, have less resistance. For example, copper has less resistance than gold, and gold has less resistance than aluminum. The weight of a conductor, the voltage run through a conductor, the grounding of a conductor, and the height of a conductor (without knowledge of its width) are unrelated to resistance.

15. The unit of measurement for capacitance is the: a. ohm. b. farad. c. watt. d. volt.

The correct answer is "b." The unit of measurement for capacitance is farads (named for the 19th-century scientist Michael Faraday). The Ohm is a measure of resistance, the Watt is a measure of power, and the Volt is a measure of electrical potential.

1. On an initial test, a telephone line reads 500 ohm tip-ring resistance. What is the most likely cause of this reading? a. The line is open b. The telephone is off the hook c. The line is grounded d. The meter isn't calibrated properly

The correct answer is "b." When a telephone is off-hook, it will have a resistance measured across the tip and ring of about 500 ohm. An open line is inconsistent with a reading of 500 ohm because there will be no connectivity between the tip and ring. A grounded line can result is a variety of readings depending on the location of the ground. Since a rating of 500 ohm signifies that the telephone is off-hook, and is therefore a plausible reading, it is unlikely that the meter has been improperly calibrated.

17. Which of the following is used to measure the output of a battery? a. TDR b. Wattmeter c. Voltmeter d. Any of the above

The correct answer is "c." A TDR (Time Domain Reflectometer) measures the length of a cable or the distance to a fault, a wattmeter measures power, and a voltmeter measures electrical potential (voltage). A battery's output is electrical potential, which is measured in volts.

29. A good ground is an important part of an installation for all of the following reasons EXCEPT: a. It helps reduce damage in case of a lightning hit. b. It eliminates any chance of personnel being electrocuted if a short occurs to a frame or cabinet. c. It protects sensitive electronics from electrical static discharge during installation. d. It is required by most manufacturers, industry practice, and electrical codes.

The correct answer is "c." A good ground will not protect sensitive electronics from electrical static discharge during installation. Static discharge can, for example, result from handling electronic components or using packaging material improperly, neither of which is related to grounding. By contrast, a good ground will reduce damage in a lightning hit during installation by shunting the voltage from the lightning strike to the ground (since the path to the ground has the least resistance). This will divert most of the energy away from regular wiring. A good ground will also eliminate the chance of electrocution if a short occurs during installation by diverting the stray voltage to the ground.Finally, most manufacturers, industry standards, and electrical codes require a good ground.

A technician is making an in-line splice as part of a buried drop installation. Approximately how much outer sheath should be removed from each end of the piece of service wire being added? a. 2 inches b. 4 inches c. 12 inches d. 24 inches

The correct answer is "c." The industry standard for splicing in-line buried drop cables is to remove 12 inches of the outer sheath before wrapping the splice to protect against water and moisture seepage into the splice. Four inches is too short and 24 inches is wasteful.

30. Today's laptop computers primarily use ____ operating systems: a. DOS b. UNIX c. Windows d. Excel

The correct answer is "c." The question asks which operating system is PRIMARILY used by today's laptop computers. DOS is sometimes used, but it is an older operating system used only on rare occasions for older programs that were created before the Windows Platform came out. UNIX is used in many engineering systems (and is the base of the MAC OS10 system), but it is not the primary operating system for today's laptop computers. Excel is not an operating system at all, but is instead an application used inside the operating system.

13. The United States standard for an alternating current is: a. 36 cycles per second. b. 48 cycles per second. c. 60 cycles per second. d. 72 cycles per second.

The correct answer is "c." There are two worldwide standards that deal with the frequency of commercial alternating current (AC) electrical service: 50 Hz (Hertz, or cycles per second) and 60 Hz. North America, including the United States, is standardized on 60 Hz

In the schematic diagram below, the circled symbol represents a: a. capacitor. b. battery. c. switch. d. resistor.

The correct answer is "c." This question represents several electrical symbols, each with well-established meanings, according to telecommunications industry standards, and their use in a schematic diagram of a circuit. The circled symbol is used to represent a switch.

20. One of the diodes in a full wave bridge rectifier opens. The DC output voltage will: a. increase. b. stay the same. c. change polarity. d. be pulsing.

The correct answer is "d." A full wave bridge rectifier is composed of four diodes configured to convert AC to DC. If one of the diodes should open, the DC output will lose part of the AC phase conversion to DC, resulting in a period of zero DC output during each cycle of the AC (as would be produced by a half wave rectifier circuit). This is observable on an oscilloscope as a pulsing output with the voltage falling to zero and remaining there for a half wave period.

10. At which of the following locations can telephone company-owned ducts be sealed at both ends? a. Ducts connecting one pole to another b. Ducts connecting one building to another c. Ducts connecting one manhole to another d. All of the above

The correct answer is "d." In this context, a duct is a pipe, tube, or conduit through which cables or wires are passed. Ducts must always be sealed on both ends to prevent moisture and foreign objects from entering. Location is irrelevant.

11. When must a telephone service technician wear a safety harness while working aloft on a telephone pole? a. Only when the pole is shared by electric utility lines b. Only when working under another employee c. Only when climbing with "hooks" d. A safety harness must be worn whenever a service technician works aloft on a telephone pole

The correct answer is "d." OSHA regulations require the use of safety equipment to protect employees whenever they are working in situations in which injury or death could occur. The purpose of a safety harness is to protect employees from hazards associated with working in situations where a fall may injure or kill them. Working aloft on a telephone pole is one such situation. As 31 Notice: Not for use/disclosure outside the Verizon Corporation or any of its subsidiaries except under written agreement. such, a safety harness is required whenever a telephone service technician works aloft on a telephone pole.

21. Which of the following is the best conductor of electricity? a. Aluminum b. Copper c. Brass d. Silver

The correct answer is "d." Of the four conductors listed, silver has the least resistance, followed by copper, aluminum, and brass. As such, silver is the best conductor. It is also, however, the most expensive. Because of the cost factor, copper is the most commonly used conductor.

5. When connecting telephone service to a mobile home, where should the protector be mounted? a. On the outside wall of the mobile home. b. At least six feet from the mobile home c. It is not needed because the mobile home is not grounded. d. On a post or pole about one foot from the mobile home.

The correct answer is "d." Protectors must be mounted on a rigid structure that is attached to the ground so that a ground wire can be securely attached to the protector. A mobile home is not structurally attached to the ground, so the protector must be mounted on a post or pole. The distance between the mounted protector and the mobile home should be about 12 inches, per industry standards.

9. What is the best location for a 66 punch-down block? a. On a pole b. In a manhole c. On the rear wall of a building d. Inside an office building

The correct answer is "d." The 66 punch-down block is a device used to connect one group of wires to another. This device is not weatherproof and is used indoors rather than outdoors. Using it outdoors would cause the connections to corrode.

12. A telephone service technician should use traffic cones: a. only when there is heavy traffic. b. when there are children on site. c. only when he/she needs to block a street. d. when parking his/her service vehicle at a public area work site.

The correct answer is "d." When a telephone service technician performs an installation, maintenance, or repair activity at a public area work site, traffic cones are needed to: (1) provide a visible warning to other traffic, vehicular and pedestrian, that the service vehicle is parked and to stay clear of the work area; and (2) to serve as a reminder to the service technician to inspect the work area before departing or moving the service vehicle. As such, the use of traffic cones is limited neither to conditions involving only heavy traffic, nor to situations when a service technician needs to block a street. Moreover, the purpose of traffic cones is to ensure that not only children, but all pedestrians and vehicles, stay clear of the work area.