Download Apprentice Lineman Exam Questions and Answers and more Exams Medicine in PDF only on Docsity!
Apprentice Lineman General Knowledge
Exam UPDATED QUESTIONS AND
CORRECT ANSWERS
What year was the IBEW formed, and who was its President? - CORRECT ANSWER 1890, Henry Miller What should be checked for when examining as injured person? - CORRECT ANSWER 1. Breathing
- Pulse
- Head Injury
- Paralysis on one side of the face
- Laryngectomee
- Stains and burns on or around mouth What is shock? - CORRECT ANSWER A depressed state of all body functions due to failure of the circulatory system. What are some signs of shock? - CORRECT ANSWER 1. Increased shallow breathing
- Cold clammy skin
- Low body temperature How should shock be treated? - CORRECT ANSWER 1. Maintain normal body temperature
- Ensure adequate oxygen supply
- Keep warm
- Control bleeding if necessary lie down with head lower than feet
- Do not move unless necessary
What are ways to control bleeding? - CORRECT ANSWER Direct pressure on pressure point and in extreme cases tourniquet. What is artificial respiration? - CORRECT ANSWER The forcing of air into the lungs of one who cannot breathe for himself. How deep should a gain be cut? - CORRECT ANSWER 1/2" Poles set on curves, corners, and strain points should be set __________ inches deeper. - CORRECT ANSWER 6 If a pole is set near an energized line what precautions should be taken? - CORRECT ANSWER 1. Cover with protective equipment
- Feeder holds
- Rubber gloves Wood poles are classified by their: - CORRECT ANSWER 1. Height
- Top circumference
- Circumference 6' from the bottom of the pole The denominator of an improper fraction is __________ than the numerator. - CORRECT ANSWER smaller What materials do electrons travel freely through? - CORRECT ANSWER conductors If few electrons travel freely through a material, that material is said to be an _________. - CORRECT ANSWER insulator Is there such a thing as a perfect insulator? - CORRECT ANSWER no
What is the most common cause for lost power? - CORRECT ANSWER heat How many watts are in one horsepower? - CORRECT ANSWER 746 One watt equals __________ horsepower? - CORRECT ANSWER. 1/ What is a watts definition? - CORRECT ANSWER The power used when one amp flows with one volt. What is the speed of light? - CORRECT ANSWER 186,000 miles per second What NECA district covers outside work exclusively? - CORRECT ANSWER Tenth District What is a guy? - CORRECT ANSWER A brace or cable fastened to strengthen a pole and to keep it in position. Aluminum has what conductivity, tensile strength, and weight of copper? - CORRECT ANSWER 60%, 45%, 33% One mill is equal to __________ of an inch? - CORRECT ANSWER 1/ How do you find the circular mil cross section area of a wire? - CORRECT ANSWER Square the diameter of the wire in mills. What is the mathematical expression for series resistance? - CORRECT ANSWER Rt = R₁ + R₂ + R₃ + R₄...
A circuit having only one current path is called a __________ circuit? - CORRECT ANSWER series What is the formula for determining the total current in a series circuit? - CORRECT ANSWER It = I₁ = I₂ = I₃ = I₄... Electrical energy is transformed into __________ when current flows through a resistor. - CORRECT ANSWER heat What is the formula for power in a series circuit? - CORRECT ANSWER Pt = P₁ + P₂
- P₃ +P₄... What is the formula for voltage in a parallel circuit? - CORRECT ANSWER Et = E₁ = E₂ = E₃ = E₄... What is the formula for resistance in a parallel circuit? - CORRECT ANSWER 1/Rt = 1/R₁ + 1/R₂ + 1/R₃ + 1/R₄... What is the formula for total current in a parallel circuit? - CORRECT ANSWER It = I₁ + I₂ + I₃ + I₄... What is the formula to find total power in a parallel circuit? - CORRECT ANSWER Pt = P₁ + P₂ + P₃ + P₄... What is produced when a conductor is moved through magnetic lines of force? - CORRECT ANSWER an EMF is induced A device used to convert AC power from one combination of voltage and current to another is called a __________? - CORRECT ANSWER transformer The sheet iron core of a transformer forms a closed: - CORRECT ANSWER magnetic circuit
Where: R = resistance K = specific resistance L = length of wire in feet A = circular mil area What are the specific resistance's of copper and aluminum? - CORRECT ANSWER Copper (Cu) 10. Aluminum (Al) 17.
- 10.4/17 = .6118 ...approx. 60% conductivity of Cu What is specific resistivity? - CORRECT ANSWER The resistance of a wire one mil in diameter one foot long. A generator with only two slip rings is know as a: - CORRECT ANSWER A single phase generator (alternating current). A generator equipped with a commutator delivers __________ current. - CORRECT ANSWER direct What is the equivalent resistance in a magnetic circuit? - CORRECT ANSWER reluctance What term represents the amount of current multiplied by the specific coil? - CORRECT ANSWER Ampere-turns Name three methods used to cool transformers? - CORRECT ANSWER 1. Oil
- Air
- Water
How many hertz are used in AC in the United States? - CORRECT ANSWER 60 Hz What are two types of instrument transformers? - CORRECT ANSWER Current & Potential Transformers of less that 500 kva are called __________ transformers. - CORRECT ANSWER distribution
- some texts use 200 kva, others 100 kva Transformers of 500 kva and larger are known as __________ transformers. - CORRECT ANSWER power
- some texts use 200 kva, others 100 kva How many windings does an auto-transformer have? - CORRECT ANSWER 1 What ratio does an auto transformer usually have? - CORRECT ANSWER 2: Primary metering requires both __________ transformers and __________ transformers. - CORRECT ANSWER potential, current Current transformers are connected in __________ with the load. - CORRECT ANSWER series In a large-sized generator which conductors spin and which remain stationary? - CORRECT ANSWER The armature conductors are stationary and the poles revolve. What should be done to rubber gloves each time they are used? - CORRECT ANSWER Visually inspected, air tested, check for proper voltage (dielectric strength), check for ozone cutting and mechanical damage.
Earth resistance is largely determined by what two conditions? - CORRECT ANSWER 1. Chemical ingredients in the soil
- Moisture present __________ percent of the resistance surrounding an electrode is within a radius of 6' to 10' from an electrode. - CORRECT ANSWER 90 Ground rods should be long enough to reach __________ moisture level of the soil? - CORRECT ANSWER permanent Codes require that the resistance of a driven ground shall not exceed __________ ohms. - CORRECT ANSWER 25 Grounds for lightning arrestors should be __________ than 25 ohms. - CORRECT ANSWER less What are the two types of counterpoise grounding? - CORRECT ANSWER 1. Continuos (parallel)
- Crowfoot (radial) List two methods to test that the line is dead before installing protective grounds? - CORRECT ANSWER 1. Rated and calibrated high voltage volt meter
- Fuzzing: not an accepted safe method, you may not see or hear much of anything on lower voltage primary systems, especially on a windy day or at a noisy location. These lower primary voltages can be difficult to read on certain meters even...causing many linemen to bump the phase with the ground before coming on hard with the head/bill of the ground. Just in case a mistake was made, you could pull away easier. What does a good ground require? - CORRECT ANSWER 1. Low resistance path to ground
- Clean tight connections made at proper points
- Adequate current-carrying capacity of grounding equipment. Where will the primary fuse on a CSP be located? - CORRECT ANSWER Inside the tank between the primary coil and the primary bushing. The overcurrent protective device on a CSP transformer is located where? - CORRECT ANSWER On the secondary side inside the tank between the secondary bushing and the secondary coil. Does the red warning light on a CSP transformer mean that an overcurrent exists now? - CORRECT ANSWER No When the overload circuit breakers are open, the: - CORRECT ANSWER primary is still energized What is the purpose of line hose? - CORRECT ANSWER To protect lineman from accidental contact. What is the maximum depth of an excavation without the use of shoring? - CORRECT ANSWER 4' Material and debris shall not be placed within how many inches of an open trench in which a man can work? - CORRECT ANSWER 18" What are the two types of underground cable? - CORRECT ANSWER 1. Shielded
- Non-shielded Non-shielded cable use is restricted to what voltage? - CORRECT ANSWER 7200 Aluminum conductors can be damaged by __________. - CORRECT ANSWER cold flow & galvanic action
Which principle does a transformer operate on? - CORRECT ANSWER mutual induction What is it called when a change of current in a coil induces an EMF in the same coil? - CORRECT ANSWER self induction The direction of flow of an induced EMF is always in which direction? - CORRECT ANSWER The direction that opposes the change of current that caused it. When a conductor is moved through magnetic lines of force what happens? - CORRECT ANSWER An EMF is induced A straight line drawn from the center of a circle to its outer edge is called the __________. - CORRECT ANSWER radius A straight line drawn through the center of a circle that touches the circle in two places is called what? - CORRECT ANSWER diameter The distance around a circle is called the __________. - CORRECT ANSWER circumference What is the formula to find the circumference of a circle? - CORRECT ANSWER C = 3.14 x D Where: D = diameter of circle What is the formula to find the Area of a circle? - CORRECT ANSWER A = 3.14 x R² Where: R = radius of circle To prevent a series circuit from being completely interrupted by a burn out of one lamp, __________ __________ __________ are used. - CORRECT ANSWER film disk cutout
What should always be done before opening a series circuit? - CORRECT ANSWER Drop load and take out of service. If raising a transformer causes temporary excessive strain to the pole what should be done? - CORRECT ANSWER Install a temporary guy What polarity are most residential distribution transformers? - CORRECT ANSWER Additive (below 200 kVA & below 8,660 V) What protects direct burial cable from: moisture, gases, chemicals, and mechanical injury during installation? - CORRECT ANSWER sheathes What are sheathes made of? - CORRECT ANSWER plastic or lead What is tracking? - CORRECT ANSWER Flow of electricity that causes damage to insulators. Why must you be careful to adequately ground neutral conductors? - CORRECT ANSWER So fault current can dissipate before causing damage to cable or equipment. What is the purpose of armor rods? - CORRECT ANSWER Protect the conductor from chafing, dampening vibration, protect from flashover burns. Stockbridge damper is designed to prevent what? - CORRECT ANSWER Resonant Vibration When a wye secondary is used on any bank what should be done with the neutral? - CORRECT ANSWER solidly grounded Remember:
Name two types of potheads? - CORRECT ANSWER 1. one conductor
- three conductor How is a pothead attached to the sheath of the cable? - CORRECT ANSWER wiped joint or a clamping joint What is the purpose of a pothead? - CORRECT ANSWER To separate conductors and to seal out water. What is another name for galvanic action? - CORRECT ANSWER electrolysis What determines how the secondary of a bank is hooked up? - CORRECT ANSWER customer demands What are the formulas for finding the capacity of an open bank? - CORRECT ANSWER 57.7% of total closed bank, or 86.6% of remaining cans What should be hooked up first when installing a transformer on transformer bank? - CORRECT ANSWER grounds and then neutrals What are the three ways to sag a conductor? - CORRECT ANSWER 1. Dynamometer
- Timing mechanical waves with a unisagwatch
- Transit What are the four principle types of electric discharge lamps? - CORRECT ANSWER 1. Sodium
- Mercury vapor
- Halide
- Florescent
How does an incandescent lamp work? - CORRECT ANSWER A wire filament sealed in a glass tube with the air pumped out is heated by a electric current that causes it to glow, it must be heated to 5000°F What are lamps rated output in? - CORRECT ANSWER lumens The highest value that a demand reaches is called the __________ __________. - CORRECT ANSWER Peak (max.) demand What determines the size and type of equipment necessary to supply the consumer? - CORRECT ANSWER Max. demand What is the formula to determine load factor? - CORRECT ANSWER Load Factor = Average Demand ÷ Maximum Demand How much can a booster transformer boost line voltage? - CORRECT ANSWER 5% or 10% How should the secondary coils be connected to boost the voltage 5%? - CORRECT ANSWER parallel How should the secondary coils be connected to boost the voltage 10%? - CORRECT ANSWER series A booster transformer is connected with the primary in __________ with the line, and the secondary in __________ with the line. - CORRECT ANSWER parallel, series What are the three types of overhead line faluts? - CORRECT ANSWER 1. Open circuit
- Cross circuit (phase to phase)
- Short circuit (phase to ground)
The unit of measurement of capacitance is the __________. - CORRECT ANSWER farad (C is used in formulas) 1 farad is the capacitance of a capacitor having an equal and opposite charge of 1 coulomb on each plate and a potential difference of 1 volt between the plates. The larger the farad value, the more charge a capacitor can hold. The unit of measurement of inductance is the __________. - CORRECT ANSWER henry (abbreviated H, L is used in formulas) A coil has an inductance of 1 henry when a current change of 1 ampere per second causes an induced voltage of 1 volt. The henry is a value based on the physical characteristics of the inductor (coil). Why does inductance have a greater effect on AC circuits than it does on a DC circuit? - CORRECT ANSWER The fields are always changing, causing a break in flux lines. Define electro-magnetic induction. - CORRECT ANSWER The process of inducing a voltage in a conductor by the action of a magnetic field. What is inductance? - CORRECT ANSWER The ability of a magnetic field to induce a voltage in a conductor. Measured in Henry's Define capacitance (C). - CORRECT ANSWER The ability of a circuit or component to store an electric charge. Measured in farads. or The ratio of the electric charge transferred from one to the other of a pair of conductors to the resulting potential difference between them.
Define capacitive reactance (Xc). - CORRECT ANSWER The opposition to the flow of current in an AC circuit due to capacitance (caused by a capacitor). Measured in Ohms. Xc = 1 ÷ (2 x 3.14 x ƒ x C) Where: Xc = capacitive reactance ƒ = frequency of the applied voltage measured in hertz C = capacitance in farads Define impedance (Z). - CORRECT ANSWER The total opposition to the flow of current in an AC circuit. or The vector sum of the oppositions found in some AC circuits. The vectors may include inductive reactance, capacitive reactance, and resistance. The vector addition of these components results in the total opposition to the AC current flow. Measured in Ohms. What is power factor? - CORRECT ANSWER The ratio of true power in watts to apparent power in volt-amps. or A factor applied to the apparent power to yield a true power. The power factor decimal is expressed as a percentage. It is also the ratio of watts divided by volt-amperes expressed as a percentage of true watts compared to apparent volt-amperes. When a circuit has a large portion of its impedance made up of inductive reactance it will have a __________ power factor and a __________ current. - CORRECT ANSWER low, lagging
