CWEA E/I 2 Study Guide Questions with Correct Answers, Exams of Workplace Safety

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Receiving job instruction and planning equipment use are part of: a. craft data. b. job preparation. c. work factors. d. leveled time. b. job preparation Anticipating other tasks or problems: a. usually creates additional problems. b. wastes time. c. sharply reduces the number of emergencies. d. often is not worth the effort. c sharply reduces the number of emergencies Making job planning a group effort: a. wastes time. b. improves productivity.

c. causes confusion. d. All the above b improves productivity Rubber safety gloves should be tested how often? a Every 12 months b. Every 9 months c. Every 6 months d. Every 4 months a Every 12 months Rubber safety blankets should be tested how often? a. Every 6 months b. Every 9 months c. Every 12 months d. Every 18 months b Every 9 months What is the interrupting current of a GFIC receptacle? a. 20 VAL b. 5 MA c. 10 UDL d. 20 MA b 5 MA What type of stepladder is forbidden while working on electrical equipment? a. Wood b. Fiberglass c. Aluminum d. Ceramic c Aluminum What is the killer of electrical shock? a. Voltage b. Current

c. Resistance d. Ohms b Current The relationship between an electric current and a magnetic field is called: a. matter. b. atoms. c. electromagnetism. d. element c electromagnetism Electrons flowing from one place to another make a: a. current. b. track. c. circuit. d. channel a current Between two objects, the development of static charges creates a: a. potential difference. b. battery. c. thermocouple. d. resistance a potential difference A coil of wire that carries an electric current is called a: a. conductor. b. thermocouple. c. electrocurrent. d. electromagnet d electromagnet

Metals are good conductors because they have many: a. insulators. b. free electrons. c. resistors. d. inductors. b free electrons The amount of potential difference a layer of insulation can withstand without breaking down is: a. resistance. b. voltage drop. c. dielectric strength. d. ampacity c dielectric strength What is the property of a coil of wire that opposes any change in the current in the coil? a. Inductance b. Resistance c. Impedance d. Watts a Inductance What is the correct name for "voltage" or electromotive force? a. Element b. Electron c. Circuit d. Potential difference d Potential difference A rate of flow of one coulomb per second is called one: a. ampere. b. joule.

c. volt. d. olhum. a ampere What is the name for the proportional relationship between potential difference and current? a. Voltage drop b. Voltmeter c. Ampmeter d. Watt meter b Voltmeter What is the unit of measurement for capacitive reactance? a. Volts b. Ohms c. Amps d. Power factor b Ohms Power companies use AC generators because AC can be sent over long distances: a. at high cost. b. at low cost. c. slower. d. faster. b at low cost What device changes alternating current to a different combination of voltage and current? a. Generator b. Capacitor c. Alternator d. Transformer d Transformer

How does the power going into a transformer compare to the power coming out? a. Lower b. Equal c. Double d. Higher b Equal What changes continuously around the conductor when current changes continuousl in AC circuits? a. Voltage b. Current c. Magnetic field d. Amps c Magnetic field Wires and cables can be classified according to their: a. color. b. size. c. covering. d. shape. c covering. What kind of starter provides full-voltage starting? a. Across-the-line b. Synchronous start c. Reactor starter d. Reduced-voltage start a Across-the-line The choice between across-the-line starting and reduced-voltage starting depends in part on the size of the: a. starter. b. wire size.

c. motor. d. breaker. c motor. The most important requirement for good maintenance of motor starters is: a. good record keeping. b. safety of personnel. c. proper lubrication. d. clean, dry insulation c proper lubrication A reversing starter reverses a three-phase motor by interchanging: a. main contacts. b. two of the line leads. c. all of the line leads. d. control voltage. b two of the line leads What kind of protection is provided in a manual across-the-line three-phase motor control? a. Overload protection only b. Ground-fault protection only c. Short-circuit protection only d. All of the above a Overload protection only Commonly used instead of fuses in industrial power distribution systems are: a. disconnects. b. motor starters. c. overcurrent relays. d. circuit breakers. d circuit breakers.

Distribution protection usually consists of two elements, protection of both: a. equipment and circuit. b. personnel and equipment. c. wire and control relay. d. ground fault and current. a equipment and circuit What is the current in amperes of a 120-volt circuit with a resistance of 60 ohms, using Ohm's Law? a. 0.5 amperes b. 2.0 amperes c. 30 amperes d. 10 amperes b 2.0 amperes Solving for I: I = ER Substituting values into the equation: I = 120 volts/60 Ohms = 2 amperes What is the current for a 120-volt circuit with a 1440-watt load? a. 0.083 amperes b. 10 amperes c. 12 amperes d. 15 amperes c 12 amperes Since P = EI, current can be determined as I = P/E Substituting values into the equation: I = 1440 watts /120 volts = 12 amperes What is the current of a circuit that consumes 625 watts through a 12.75-ohm resistor? a. 3.8 amperes

b. 7 amperes c. 49 amperes d. 175 amperes b 7 amperes E = IR and P = EI Substituting the first equation into the second: P = (IR)I P = I Squared x R Solving for I: I Squared = P / R I = SqRt P/R I = SqRt 625/12. I = SqRt 49 I = 7 amps What is the ampere load of a single-phase 1/2 horsepower 115-volt motor, if the motor has an efficiency rating 92% and power factor of 80%? a. 9.5 amperes b. 2.4 amperes c. 4.4 amperes d. 78.1 amperes c 4.4 amperes Use the formula I = 746 x horsepower / voltage x efficiency x power factor, where I is the current. I = 746 x 0.5 / 115 x 0.92 x 0.80 = 4.4 amperes A 230-volt single-phase circuit has a 12-kilowatt power load and operates at 84% power factor. What is the current? a. 43 amperes b. 52 amperes c. 62 amperes d. 70 amperes c 62 amperes the formula I = kilowatts x 1.000 / voltage x power factor

where I is the current. I = 12 x 1.000 / 230 x 0.84 = 62 amperes The difference between the measurement signal and the set point is called the: a. gap. b. error. c. feedback. d. span. b error The signal pressure is usually directly proportional to the process: a. span. b. level. c. variable. d. loop. c variable Offset is the difference between the actual maintained value of the measured variable and: a. the set-point. b. the span. c. zero. d. the level. a the set-point Another name for built-in error that usually occurs in a proportional control system is: a. deadband. b. offset. c. set point. d. span. b offset An automatic controller always compares a measured variable to:

a. zero. b. span. c. reset. d. set point. d set point. The specific value at which an automatic control holds a process variable is called the: a. span. b. variable. c. control point. d. set point. c control point The drawing that provides a view of the entire system in process control is the: a. P&ID drawing. b. I/P drawing. c. element drawing. d. primary drawing. a P&ID drawing A tag number with a code reading FRC identifies a. field recording controller. b. flow recorder controller. c. temperature controller. d. pressure recorder. b flow recorder controller The most commonly used type of diagram in process control is: a. a loop diagram. b. an installation drawing. c. a piping and instrument drawing. d. a location drawing.

c a piping and instrument drawing A signal from a measuring device to the controller is called: a. zero. b. correcting. c. span. d. feedback. d feedback. In a closed loop control system, the control process of measuring, comparing, computing and connecting goes on: a. continually. b. intermittently. c. never. d. whenever the operator takes some action. a continually A control system in which the output is regulated only by changes from outside the process is called: a. open loop. b. closed loop. c. set point. d. measuring. a open loop. A common converter used in process control is the I/P converter, which converts ________ signals to ________ signals. a. zero, span b. analog, digital c. current, pneumatic d. linear, nonlinear c current, pneumatic

Time lag can be defined as the time between: a. turning an instrument on and off. b. a high reading and a low reading. c. a proportional reading, and an inverse reading. d. input to a instrument & output from an instrument. d input to an instrument and output from an instrument Name the three most common mediums of data transmission. a. Twisted pair, radio, fiber optics b. Phone, telemetry, radio c. Cable, phone, radio d. Coax, phone, fiber optics a Twisted pair, radio, fiber optics The small region of an instrument range where input changes cause no corresponding output change is called: a. range. b. deadband. c. span. d. linear. b deadband Instrument error is usually expressed as: a. percent. b. span. c. zero. d. linear. a percent A pressure-transmitting system is one in which the signal tubes are filled with: a. air.

b. liquid. c. mercury. d. acid. b liquid In supervisory control, the computer plays a(n): a. analog role. b. inactive role. c. active role. d. plotter role. c active role The abbreviation SCADA stands for: a. Safety Control and Data Answering. b. Supervisory Control and Data Acquisition. c. System Computer and Digital Analog. d. Self Contained and Data Acquisition. b Supervisory Control and Data Acquisition Communicating process data to and from the SCADA computer is the purpose of the: a. conditioning system. b. transmitting system. c. control system. d. interface system. d interface system A computer program operates under the control of a(n): a. operating system. b. controller system. c. interface system. d. process system. c interface system

The configuration in which individual computers are connected for purpose of communication is a a. CPU. b. BIU. c. network. d. loop. c network The abbreviation LAN stands for: a. Level Alarm Network. b. Loop Alarm Neutral. c. Local Alarm Network. d. Local Area Network. d Local Area Network Whole circuits manufactured with all components in place and ready to work are called: a. semiconductor circuits. b. microprocessor circuits. c. rectifier circuits. d. integrated circuits. d integrated circuits What is the psi if the height of a column of water is 55.4 inches? a. 2 psi b. 4.1 psi c. 27 psi d. 55.4 psi a 2 psi This is a conversion problem that use formula: 27.7 inches of water = 1 psi Therefore: 54.4 inches x 1 psi / 27.7 inches = 2 psi How many inches of mercury are required to obtain a pressure of 4 psi?

a. 4 inches b. 8.144 inches c. 54.4 inches d. 110.8 inches b 8.144 inches This is a conversion problem that use formula: 1psi = 2.036 inches of mercury (Hg) at 32° F Therefore: 4 psi x 2.036 inches Hg / 1 psi = 8.144 inches Hg 77°F is equal to how many degrees Celsius? a. 81°C b. 60°C c. 43°C d. 25°C d 25°C To change from the Fahrenheit scale to Celsius scale, use formula: °C = 5/9 (°F - 32°) Therefore: °C = 5/9 (77° - 32°) °C = 5/9 (45°) °C = 25 The supply of spare parts, tools, and test instruments should be monitored by the: a. supervisory control operation. b. limited control operation. c. computer control operation. d. inventory control operation. d inventory control operation Which of the following is the best choice of work clothing fabric when working with electricity? a. Cotton b. Nomex

c. Nylon d. Polyester b Nomex The best combination of gloves to wear when performing electrical work is: a. leather over rubber. b. leather over cotton. c. synthetic over rubber. d. synthetic over cotton. a leather over rubber Which of the following is a function of the tag and lockout disconnect switch? a. Give instructions for the work to be performed b. Identify the individual who placed the lock c. List all affected sub systems d. Prevent accidental startup b Identify the individual who placed the lock When working with electricity, it is especially important to inspect tools for: a. bent shafts. b. cracked handles. c. damaged insulation. d. work tips. c damaged insulation Voltage testers are typically used to: a. cut off power to a circuit. b. distinguish between AC and DC circuits. c. measure potential differences. d. verify that the circuit is de-energized. d verify that the circuit is de-energized

What is the main electrical danger when using power tools? a. Excessive heat b. Low resistance grounding c. Overcurrent d. Short circuit d Short circuit How many gallons of water will it take to fill a 3 cubic foot container? 3 cubic feet x 7.48 gallons cubic feet = 22.4 gallons If a gallon of gasoline weighs 7.0 pounds, what would be the weight of a 350 gallon tank full of gasoline? 350 gallons x 7.0 pounds / gallons = 2,450 pounds The rated capacity of a pump is 500 gallons per minute (GPM). Convert this capacity to million gallons per day (MGD). 500 GPM x 1 MGD / 694 GPM = 0.72 MGD A chemical feed pump is calibrated to deliver 50 gallons per day (GPD). What is the calibrated chemical feed in gallons per minute (GPM)? 50 gal / day x 1 day / 24hr x 1 hr / 60 min= 0.035 GPM A chemical feed pump delivers 50 mL per minute (mL/min). Determine the chemical feed in gallons per day (gpd). 50 mL / min x 1 L / 1000mL x 1 gallon / 3785 L x 60 min/ hour x 24 hr/ day =19 GPD A cyanide destruction process is designed to treat 30 pounds of cyanide per 24-hour operational day. How many pounds of cyanide can be treated during an 8-hour shift?

30 lbs CN / day x 8 hr / shift x 1 day / 24 hr = 10 lbs CN/shift Find the volume of water required to fill a sewer pipe that measures 500 feet in length and has an 18-inch diameter. Express your answer in gallons. Diameter = 18 inches x 1 foot / 12 inches = 1.5 foot Vol = 0.785 x diameter2 x height = 0.785 x (1.5 ft)2 x 500 feet = 883 cubic feet Vol = 883 cubic feet x 7.48 gallons / 1cubic foot Volume of water = 6,605 gallons A resistor's first three colour bands are; brown, black, and red, What is its value? A 10 Kohms B 10 ohms C 1000 ohms D 200 ohms C 1000 ohms The colour bands are read from left to right. First band denotes first digit, second band second digit, and third band denotes subsequent number of zeros Which digit does the colour yellow denote on a resistor colour band? A 4 B 7 C 2 D 3 A 4 The digits are denoted by the different colours, black = 0, brown=1 red=2, orange=3, yellow=4, green=5 blue= violet=7 grey = 8 white = 9 A resistor's first three colour bands are; red, yellow, black, What is its value? A 420000 ohms B 240 ohms C 24 ohms D 32 ohms C 24 Ohms A resistor's first three colour bands are; brown, green, red, What is its value? A 152 ohms B 1500 ohms C 250 ohms D 510 ohms B 1500 ohms First digit = 1 (brown) Second digit = 5 (green) followed by two zeros (red) Bad Boys Rape Our Young Girls But Violet Gives Willingly Black, Brown, Red, Orange, Yellow, Green, Blue, Violet, Grey, White <=> 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 If the values of the three resistors in parellel are: R1= 8 Ohms R2=8 Ohms R3= 4 Ohms What is the total resistance in Ohms?

2 Ohms (1/8 = .125 + 1/8 = .250 + 1/4 =. 1/.5= 2) Basically divide all resistor values by one and add them up. Then divide 1 by answer.) If the values of the three resistors in series are: R1= 8 Ohms R2= 8 Ohms R3= 4 Ohms What is the total resistance in Ohms? 20 Ohms (8 + 8 + 4 = 20) Basically just add up values of all resistors in series. If two paralleled generators are synchronized correctly, what voltage would be read between one hot phase on one generator and one hot phase on the other? 0 Volts At what point can two synchronized generators be connected together? When reading between two hot phases is 0 Volts. This means the generators are "in phase" or synchronized. If two generators are 180 degrees out of phase, what will be the voltage between one hot phase on one generator and one hot phase of the other? The sum of the two voltages, or 2x the rated voltage of one of the generators. What is the name of the instrument used to synchronize two generators so that they are "in phase" with each other? Synchroscope. (Used to test whether plants electrical bus and generator are "in phase" prior to connecting a generator to a live bus. If not the rotor of generator will be yanked into phase, damaging the generator.) When using lights connected between two hot phases of two generators to synchronize, how do lights burn when in phase, 180 degrees out phase, and when one generator faster than the other? In phase = Lights will not burn 180 out phase = Lights burn full brilliance Faster than other = Lights will flicker because will be out phase(burn bright) than in phase(not burn). If the potential difference across the coil is low, the coil will: a. draw too much current. b. become too hot.

c. produce too much magnetic force. d. not heat up. d. not heat up The NEC identifies environments that contain flammable vapors and gases as which class of hazardous locations? a. Class I b. Class II c. Class III d. Class IV a. Class I Which of the following reduces high voltages and currents to safe values for measurements? a. Auto transformer b. Megohmmeter c. Instrument transformer d. Variable transformer c. Instrument transformer In a three-wire control circuit, when a power failure occurs: a. the interlock contact will close the circuit. b. the operator can restart the meter automatically. c. the motor can restart unexpectedly. d. the operator must restart the meter manually. d. the operator must restart the meter manually. Pushbuttons are classified as standard-duty or heavy-duty according to the: a. kind of enclosure. b. service conditions. c. frequency operation. d. current carrying ability. d. current carrying ability

A push-to-test pilot light is used in applications where the pilot light is: a. rarely needed. b. a neon bulb. c. used only in DC applications. d. in constant use. a. rarely needed. The advantage of LCDs over LEDs is: a. accuracy. b. better visibility. c. lower power consumption. d. sensitivity. c. lower power consumption Shielding protects an analog meter from: a. damage due to careless handling. b. harmful UV rays. c. over-current and surges. d. stray magnetic fields. d. stray magnetic fields An ammeter should be connected: a. across the line. b. around an inductor. c. in parallel with the load. d. in series with the load. d. in series with the load. Bar graphs and wave forms can be displayed on a LCD screen when the multimeter has: a. analog/digital circuits. b. microprocessor circuitry. c. opposing coils and a commutator. d. parallel ports. b. microprocessor circuitry

The difference between the squirrel-cage rotor and the wound rotor is in: a. their pole-phase groups. b. how the conductors are connected. c. how the current is induced in the conductors. d. all of the above. b. how the conductors are connected The frame, the core, the winding, and the end plates are all parts of the: a. rotor. b. stator. c. alternator. d. induction motor. b. stator Which of the following is a sign of overheating rotor bars? a. Reduced starting torque. b. Noise. c. Discoloration. d. All of the above c. Discoloration Two sources of power, one AC and one DC, are required for running a(n): a. induction motor. b. squirrel-cage motor. c. synchronous motor. d. wound-rotor motor. c. synchronous motor. Modern synchronous motors have: a. both brushes and slip rings. b. brushes, but no slip rings. c. slip rings, but no brushes. d. neither brushes nor slip rings. d. neither brushes nor slip rings

All the following are true of 240-volt systems compared to 480-volt systems, except: a. they cost more to operate. b. they require more current per unit of power. c. they require smaller circuit breakers. d. they are safer c. they require smaller circuit breakers If a charged capacitor is removed from a circuit, the capacitor: a. retains its charge. b. loses some of its charge. c. loses most of its charge. d. loses all of its charge. a. retains its charge Control systems are usually designed so that each individual circuit controls: a. all functions of the machine. b. at least two functions. c. only one function. d. only one device. c. only one function A 115-volt, 2-KVA, single-phase generator operating at full load will deliver how many amperes? a. 0.23 b. 17.4 c. 57.5 d. 230 b. 17.4 What is the current when a circuit has a 1,500-watt load and a power factor of 86%, and operates from a three-phase 230 - volt source? a. 9.7 amps b. 6.5 amps c. 4.4 amps d. 3.8 amps

c. 4.4 amps What is the amp-load of a three-phase, 0.5-hp, 230-volt motor with an efficiency rating of 92% and a power factor of 80%? a. 1.27 amps b. 1.19 amps c. 2.55 amps c. 4.41 amps a. 1.27 amps A three-phase, 460-volt motor draws a current of 52 amperes. The motor has an efficiency rating of 94% and a power factor of 80%. What is the horsepower? a. 24.1 hp b. 41.7 hp c. 50.0 hp d. 73.8 hp b. 41.7 hp A 120-volt AC circuit draws a current of 5 amperes. Determine the power consumption. a. 60 watts b. 120 watts c. 4.8 watts d. 600 watts d. 600 watts

1. In a simple ratio system, the independent variable is: a. both measured and controlled. b. controlled but not measured. c. measured but not controlled. d. neither measured nor controlled. c. measured but not controlled
2. The root-mean-square method is used to calculate: a. integral and derivative action. b. proportional band or gain.