Basic Electricity Practice Exam

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• With power to the bus and the fuel selector switched to the right-hand tank, how many relays in the system are operating?
• What factors strengthen a coil inductor?
• A 10 Ω resistor carries 2 A. What is the power dissipated by the resistor?
• The current through the 20-watt lamp connected to a 30-volt source in the parallel circuit is approximately which value?
• What is the relationship between mechanical and electrical power?
• Which instrument is used to measure voltage?
• How many significant digits are indicated by the 5-band resistor code compared to the 4-band code?
• Using the relation R = E^2 / P, what is the resistance of a device that draws 48 watts from a 24-volt source?
• Capacitors are sometimes used in dc circuits to ________.
• For RC values R = 1 kΩ and C = 1 μF, what is the time constant τ in seconds?
• In a DC steady-state circuit containing an inductor, what is the inductor's impedance behavior?
• A cabin entry light of 10 watts and a dome light of 20 watts are connected in parallel to a 30-volt source. If the voltage across the 10-watt light is measured, it will be _________.
• To measure resistance, which meter function should be used and how should you prepare the circuit before measuring?
• The working voltage of a capacitor in an AC circuit should be __________.
• In a parallel circuit with four 6-ohm resistors across a 24-volt battery, what is the voltage across resistor-three (VR3)?
• For the circuit described, what is the total current?
• The electrolyte of a nickel-cadmium battery is the lowest when the battery is ______.
• If the supply voltage doubles while the total resistance remains constant, the total current will
• When the landing gears are up and the throttles are retarded, the warning horn will not sound if an open occurs in wire ________.
• What is the basic unit of current flow?
• A 2 kW heater runs for 3 hours. How many kilowatt-hours does it consume?
• What is the purpose of providing space underneath the plates in a lead-acid battery's cell container?
• In a parallel circuit with three resistors, which statement is true?
• In DC circuits, what is the conventional direction of current relative to electron flow?
• The control valve switch must be placed in the neutral position when the landing gears are down to ________.
• If a circuit delivers fixed real power and power factor is improved, the current will:
• Which unit is used to measure current?
• Diodes are used in electrical power supply circuits primarily as ______.
• In an RC charging circuit, after a long time, the capacitor voltage approaches what value relative to the supply?
• How can the state-of-charge of a nickel-cadmium battery be determined?
• What is the primary hazard associated with arc flash in electrical work?
• Which of these will cause the resistance of a conductor to decrease?
• Which color represents the tolerance band in a 4-band resistor with colors Yellow, Violet, Red, Gold?
• How much current flows through each of the three resistors connected in series if the total current is 3 amps?
• If the frequency is 60 Hz, what is the angular frequency ω?
• What is meant by resistance in an electrical circuit?
• What is the measured voltage of the series-parallel circuit between terminals A and B?
• Convert 1 kW to watts and 1 μF to farads.
• Which arrangement strengthens a coil inductor?
• In an AC circuit, the current or voltage values are typically specified as which type of value?
• The nickel-cadmium battery spill neutralization uses which solution?
• What is the total capacitance of a circuit containing three capacitors with capacitances of .02 microfarad, .05 microfarad, and .10 microfarad, respectively?
• Which of the following describes the effect of servicing nickel-cadmium and lead-acid batteries in the same service area?
• In a circuit, if the cross-sectional area increases while the length remains the same, the current for a fixed voltage will
• What is the voltage across each resistor connected in parallel across a 12-volt battery?
• A 1,500 W heater runs for 2 hours. How many kilowatt-hours does it consume?
• When different rated capacitors are connected in parallel, the total capacitance is equal to which of the following?
• For the series circuit above, what is the impedance phase angle φ between voltage and current?
• A thermal switch, or thermal protector, as used in an electric motor, is designed to _________.
• In a resistor circuit with R = 4 Ω and current I = 2 A, what is the voltage across the resistor?
• In an NPN transistor, the device turns on when the emitter is positive with respect to the base.
• What is the resistance of an open circuit?
• In what units is impedance measured?
• What constitutes a capacitor?
• In a 5-band resistor code, how many significant digits are indicated?
• Under which condition will a ground be provided for the warning horn through both gear switches when the throttles are closed?
• What will a voltmeter read if properly connected across a closed switch in a circuit with electrical power on?
• A 0.2-horsepower, 24-volt motor with 75 percent efficiency requires approximately how many watts of input power?
• A 24-volt source is required to furnish 48 watts to a parallel circuit consisting of four resistors of equal value. What is the voltage drop across each resistor?
• Typical application for zener diodes is as __________.
• A 50 mH inductor carries 2 A. What is the energy stored?
• If you double the plate area of a capacitor while keeping the plate separation and dielectric constant constant, what happens to the capacitance?
• If a device has voltage 24 V and current 3 A, what is its resistance?
• What is the resistance of each resistor in the 24-volt parallel circuit described to yield a total of 48 watts across four equal resistors?
• In a parallel lighting circuit, if one of the three bulbs is removed, what happens to the total resistance?
• For N identical capacitors connected in parallel, what is the equivalent capacitance Ceq?
• In an RC charging circuit with R = 10 kΩ and C = 100 μF, what is the time constant τ?
• The energy stored by a capacitor is in what type of field?
• What is the basic unit of electrical resistance?
• A circuit has an applied voltage of 30 volts and a load consisting of a 10-ohm resistor in series with a 20-ohm resistor. What is the voltage drop across the 10-ohm resistor?
• If the primary voltage is 240 V for this transformer, what is the secondary voltage?
• A capacitor has Q = 5 μC and V = 2 V. What is the capacitance?
• What three things must an electric circuit contain?
• What is the purpose of a capacitor?
• With a transformer having primary turns 200 and secondary turns 50, if the secondary current is 2 A, what is the primary current (ideal transformer)?
• In a parallel circuit with two identical resistors, the total resistance is half the resistance of one resistor.
• Which statement about equipment grounding is correct?
• The lead-acid battery capacity rating describes the number of hours at a given current, which is best described as what?
• When measuring resistance of a component with an ohmmeter, should the circuit be energized?
• The term that describes the combined resistive forces in an AC circuit is __________.
• Which of the following are commonly used as a rectifier in electrical circuits?
• Using the 14-ohm resistor example, the power dissipated equals I^2 R; if I = 0.05 A, P equals 0.035 W.
• A 5-band resistor has bands Brown, Black, Black, Red, Gold. What is its resistance and tolerance?
• An inductor of 2 mH carries 3 A. What is the energy stored in the inductor?
• If the left gear is up and the right gear is down, and the throttles are closed, which condition allows the warning horn to be grounded through gear switches?
• A 28-volt generator powers five lamps in parallel: three of 6 ohms and two of 5 ohms. How many amperes will the generator need to supply?
• Transfer of electric energy from one circuit to another without the aid of electrical connections is called ______.
• Continuity in an electrical circuit is best described as?
• What is the basic unit of capacitance?
• In a parallel circuit with a 6 Ω branch and a 3 Ω branch across 12 V, what are the currents in each branch?
• Which statement correctly distinguishes a ground fault from a short circuit?
• If resistor R(5) is disconnected at the junction of R(4) and R(3) as shown, what will the ohmmeter read?
• How much power is being furnished to the circuit?
• What two things happen when current flows through a conductor?
• Which statement describes a series configuration?
• A circuit has real power P = 500 W and apparent power S = 600 VA. What is the power factor?
• What is the purpose of a ground fault circuit interrupter (GFCI)?
• For N identical capacitors connected in series, the equivalent capacitance is Ceq = C/N.
• In an AC circuit, impedance represents the total opposition to current, including resistance and reactance.
• In a P-N-P transistor application, the solid state device is turned on when the ________.
• The energy stored in a 100 μF capacitor charged to 10 V is what?
• In a functional circuit containing this gate, the output will be 0 only when all inputs are 0.
• What is electrical current?
• The opposition offered by a coil to the flow of alternating current, disregarding resistance, is called __________.
• In the 4-band resistor code used here, what is the multiplier value indicated by the third band?
• The total inductance of two inductors in series equals the sum of their inductances under which condition?
• What happens to the capacitance if the distance between the plates increases while the plate area remains fixed?
• What are the units of electrical frequency, and how is angular frequency ω related to f?
• What is the capacitive reactance Xc for a 100 μF capacitor at 50 Hz?
• A 50 μF capacitor charged to 20 V stores how much energy?
• What is the total capacitance of a circuit containing three capacitors in parallel with capcitances of .02 microfarad, .05 microfarad, and .10 microfarad, respectively?
• If you improve power factor in a circuit delivering a fixed real power, what happens to current?
• What is the total resistance of three 12-ohm resistors connected in series?
• What instrument is used to measure the specific gravity of the electrolyte in a lead-acid battery?
• In a circuit with three 12-ohm resistors in series (36 ohms) and in parallel (4 ohms), which statement is true?
• What are the elements of Ohms law?
• In parallel, the total inductance of more than two inductors with different inductances is always:
• Electrostatic fields are also known as __________.
• What is the inductive reactance XL for an inductor of 150 mH at 60 Hz?
• Which relays are energized when power is applied to the bus, according to the system?
• Reactive power Q for the load with P = 831 W and S = 960 VA is approximately?
• When inductors are connected in series (assuming their magnetic fields do not affect each other), the total inductance is equal to which of the following?
• In a parallel circuit with three 6-ohm resistors across a 12-volt battery, what is the current through each resistor?
• At a junction, branch currents are 5 A and 3 A entering the node. If a third branch carries current away from the node, what is its current magnitude?
• What is used to neutralize spilled electrolyte from a lead-acid battery?
• How does temperature generally affect resistance in most metal conductors?
• If a 24 V source is shorted through a 0.1 Ω resistance, what is the short-circuit current?
• Energize the circuit with the fuel tank selector switch selected to the left-hand position. Using the schematic, identify the switches that will change position.
• In a parallel circuit powered by 24 volts, the voltage across each resistor is equal to the source voltage.
• For N identical capacitors connected in series, the equivalent capacitance is Ceq = C/N.
• What is meant by inductance?
• What is the likely result of servicing and charging nickel-cadmium and lead-acid batteries together in the same service area?
• A 12 V source drives a 3 Ω resistor. What is the current through the resistor?
• What is the purpose of the ground symbol used in electrical circuit diagrams?
• Two resistors 6 Ω and 3 Ω are in parallel across a 12 V supply. What is the total current drawn from the source?
• When different rated capacitors are connected in series in a circuit, the total capacitance is ________.
• If a 120 V source is shorted through a 0.2 Ω resistance, what is the short-circuit current?
• What is the magnitude of the net reactance in the series circuit with XL = 3 Ω and Xc = 5 Ω?
• Electrical power is calculated by which of the following formulas?
• A sinusoidal voltage has an RMS value of 120 V. What is its peak value approximately?
• The green landing gear light will fail to illuminate when the landing gear is down if there is an open in which wire?
• In a DC circuit, after a long time, what is the effective resistance of an ideal capacitor, and does it conduct current?
• Which of the following loads would require the most electrical power in a given setup?
• What is used to neutralize spilled electrolyte from a nickel-cadmium battery?
• An AC circuit has impedance Z = 5 Ω and RMS current I = 2 A. What is the RMS voltage across the circuit?
• The No. 7 wire is used to _________.
• One horsepower equals how many watts?
• When electrical power is applied to the bus, which relays are energized?
• Which statement properly describes the purpose of space under plates in a lead-acid battery?
• What is the formula for power in a DC circuit?
• What is the SI unit of electric charge and its symbol?
• Which statement about hydrometer readings for lead-acid electrolyte is correct?
• In a parallel DC circuit, which statement is true?
• One horsepower is equal to how many watts?
• In the landing gear down condition, the green light will not come on if an open occurs in wire _______.
• Which component is most closely associated with dielectric fields?
• Which statement correctly defines bonding in electrical systems?
• The potential difference between two conductors that are insulated from each other is measured in which unit?
• For a sinusoidal voltage with RMS value V_rms, the peak value is approximately which factor of V_rms?
• A 24-volt source is used to supply 48 watts to a parallel circuit consisting of two resistors of equal value. What is the resistance of each resistor?
• A load draws 8 A at 120 V with a phase angle of 30 degrees between voltage and current. What are the real power P, apparent power S, and power factor PF?
• Which scenario requires the most electrical input power?
• With an ohmmeter connected into the circuit as shown, what will the ohmmeter read?
• When the landing gears are up and the throttles are retarded, the warning horn will not sound if an open occurs in wire _______.
• Find the total resistance of the circuit.
• In a transformer with Np = 200 turns and Ns = 50 turns, if 120 V is applied to the primary, what is the secondary voltage?
• When more than two inductors of different inductances are connected in parallel, the total inductance is which of the following?
• Which component is not required in a basic circuit consisting of a power source, a load, and conductors?
• A 15 Ω resistor carries 4 A. What is the voltage across the resistor?
• Regarding hydrometer readings of lead-acid electrolyte, which statement is true?
• What is the basic unit of electrical quantity?
• If resistor R(3) is disconnected at terminal D, what will the ohmmeter read?
• What is the total current drawn from the 12 V source in the parallel circuit with a 6 Ω branch and a 3 Ω branch?
• What is the total power drawn by a 24-volt system with the following loads: One motor (0.2 hp) at 75% efficiency, three 20-watt lights, a heating element drawing 5 A, and an anticollision light drawing 3 A?
• A 1-horsepower, 24-volt DC electric motor that is 80 percent efficient requires 932.5 watts. How much input power will a 1-horsepower, 12-volt DC motor that is 75 percent efficient require?
• Which is correct concerning a parallel circuit?
• What is the resistance and tolerance of a 4-band resistor with color bands Yellow, Violet, Red, Gold?
• The electrolyte of a nickel-cadmium battery is highest when the battery is __________.
• What term describes a circuit in which electrons can flow from the power source to the load and back?
• Which instrument is used to measure current?
• What is the purpose of lockout/tagout procedures in electrical work?
• If one resistor opens in the 24-volt parallel circuit with two 24-ohm resistors, what is the current from the source?
• A series circuit has R = 4 Ω, XL = 3 Ω and Xc = 5 Ω at a given frequency. What is the impedance magnitude?
• What is the total resistance of three 12-ohm resistors connected in parallel?
• When capacitors are connected in parallel, the total capacitance equals the sum of the individual capacitances. Which statement is true about this arrangement?
• To measure current through a component, is an ammeter placed in parallel or in series with the component?
• What is the total capacitance of a circuit containing three capacitors of 0.25 microfarad, 0.03 microfarad, and 0.12 microfarad in parallel?
• If you double the frequency in a circuit containing only a capacitor, how does Xc change?
• In a parallel circuit, adding another identical resistor reduces the total resistance. Which statement is true?
• The amount of electricity a capacitor can store is directly proportional to the _________.
• A parallel circuit with four 6-ohm resistors across a 24-volt source. What is the total current drawn from the source?
• How is capacitance defined in terms of charge and voltage?
• In a parallel circuit with two lamps rated 10W and 20W connected to a 30V source, the voltage across each lamp is equal to the source voltage.
• A 6 Ω resistor carries 3 A. What is the power dissipated by the resistor?
• In a simple circuit with only an 8-ohm resistor connected to a 24-volt source, what is the voltage across the resistor?
• The operating resistance of a 30-watt light bulb designed for a 28-volt system is approximately what?
• Which unit is used to measure impedance according to the material?
• Using the right-hand rule, what is the direction of the magnetic field around a straight conductor carrying current upward as viewed from above?
• Inductance stores energy in what kind of fields?
• What is the basic unit of inductance?
• In a series circuit with 2 Ω and 8 Ω resistors across a 20 V source, what is the voltage across the 2 Ω resistor?
• In an RC discharge circuit with the same R and C, what is the voltage across the capacitor after t = 2 s if the initial voltage is V0?
• To measure voltage, a voltmeter is placed in
• What does the letter Q symbol symbolize when measuring electrical charge?
• What is the turns ratio Ns/Np for this transformer?
• In an RC charging circuit with R = 1 kΩ and C = 1 μF, what is the capacitor voltage after one time constant τ if the supply is V?
• What is voltage?
• What is the resistance of a short circuit?
• With the fuel selector switch in the left-hand position and power applied to the bus, which switches will move?
• Which expression correctly represents Ohm's law using E for voltage, I for current, and R for resistance?
• A 2 W resistor dissipates 1.5 W. What percentage of its rating is being used?
• The electrolyte concentration in a nickel-cadmium battery is highest when the battery is ______.
• What is meant by impedance?
• A circuit contains a 6 Ω resistor in series with a 3 Ω resistor across an 18 V supply. What is the total resistance and the current drawn?
• Which terms are included in impedance for alternating current?
• Which statement about a multi-input OR gate is true?
• In a parallel circuit with a fixed voltage source, the voltage across each component is
• The electrolyte of a nickel-cadmium battery is highest when the battery is fully charged.
• How many phase waveforms are present in single-phase versus three-phase systems?
• In a PNP transistor, if the base is more positive than the emitter, what is the state of the transistor?
• What is meant by the capacity rating of a lead-acid battery?
• A 14-ohm resistor is to be installed in a series circuit carrying .05 ampere. How much power will the resistor be required to dissipate?
• Two resistors, 8 Ω and 4 Ω, are in parallel across a 12 V source. What is the total current drawn from the source?
• If three resistors of 3 ohms, 5 ohms, and 22 ohms are connected in series in a 28-volt circuit, how much current will flow through the 3-ohm resistor?
• What are three types of DC circuits with regard to the placement of the various circuit components?