NEIEP Electrical Theory and Application (430) Practice Exam

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• For resonance in a series RLC circuit, which condition is true?
• What defines a permanent magnet AC motor (PMAC) rotor?
• The rotor of a permanent magnet motor turns at the same speed as the stator's magnetic field.
• In a split-phase motor, the start winding is disconnected before reaching full speed.
• How does a transformer reflect impedance and why is it important for design?
• How does a multimeter measure current and what precautions are needed?
• Which motor type uses permanent magnets on the rotor?
• Which symbol represents a 3-phase motor on a schematic?
• In a Delta connection, three coils are connected in what shape?
• What is a 3-lead AC motor?
• What is synchronous speed?
• Power factor is defined as cos φ, the angle between voltage and current?
• In a squirrel cage rotor, the heavy conducting elements running parallel to the axis are called?
• Which item is typically shown on an AC motor nameplate to indicate how much overload the motor can handle continuously?
• What is the purpose of tying the neutral leads together in a wye configuration?
• What is the expression for apparent power S in terms of real power P and reactive power Q?
• Calculate synchronous speed for a 4-pole motor on 60 Hz.
• True or False: Changing the direction of current flow to a universal motor changes its direction of rotation.
• What is the formula for synchronous speed?
• How is a 12-lead motor connected for high voltage wye (example 460 V)?
• How are motor windings shown on connection diagrams?
• What is the percent slip for a 6-pole, 60 Hz motor with a nameplate speed of 1170 RPM?
• In a squirrel‑cage induction motor, the rotor is composed of which of the following?
• In a high-pass filter formed by a capacitor in series with a signal, which frequency components are attenuated?
• What is the motor term for a device designed to run on both AC and DC?
• In a balanced wye-connected three-phase system, what is the relationship between line-to-line voltage and line-to-neutral voltage?
• A 12 V DC source powers a 4 Ω resistor. What is the current and power dissipated?
• In a balanced three-phase system, which formula gives the real power P using line voltage, line current, and power factor?
• If phase sequence is ABC (counterclockwise), what is the rotation for sequence BAC?
• In a purely resistive AC circuit, what is the phase angle between voltage and current?
• What is the synchronous speed of a 12‑pole, 60 Hz motor?
• How does frequency affect the reactance of an inductor and a capacitor respectively?
• Why is power factor correction achieved by adding a capacitor in parallel with inductive loads?
• Synchronous speed is defined as the rotational speed of which component in an induction motor?
• What is the rotating speed of a three-phase 30 Hz 6-pole motor?
• In a squirrel cage rotor, the bars or rods are oriented parallel to the axis of rotation.
• Which is an advantage of PMAC motors?
• What are the two main parts of an AC induction motor?
• With a turns ratio a = 0.5 in an ideal transformer, which expression gives the reflected impedance on the primary?
• For a universal motor, current flows in the [same/different] direction through the armature and field winding?
• A transformer has a turns ratio of 2:1 (step-down). If the primary is 480 V, what is the secondary voltage ignoring losses?
• What is the purpose of a protective device in a circuit and name two common types?
• Which statement about a 12-lead motor is true?
• In a series RLC circuit, which parameter primarily determines the bandwidth around resonance, and which standard expression defines Q for a series circuit?
• What is the synchronous speed of a 60 Hz motor with 8 poles?
• How is a 9-lead motor connected for low voltage (example 230 V)?
• Which statement accurately describes a main difference between AC and DC motors?
• Which of the following is not a form of Ohm's Law?
• What is slip in an induction motor?
• Slip is defined as the percentage difference between which two speeds?
• In capacitor-start induction-run motors, at approximately what percent of rated speed is the start winding disconnected by the centrifugal switch?
• A true statement about split-phase motors is that the start winding is used only during acceleration.
• Kirchhoff's Voltage Law (KVL) and Kirchhoff's Current Law (KCL) describe which of the following statements?
• The stator's wye windings have a common connection between phases called the
• In a single-phase circuit, reactive power is Q = V I sinφ. What does a positive Q indicate about the load?
• In a Wye connection, how are the coils arranged?
• How is a 9-lead motor connected for high voltage (example 460 V)?
• If slip is zero, the rotor speed is equal to which speed?
• In a phasor diagram, which quantities are represented as vectors to show their relationship?
• In a damped parallel LC circuit at resonance, the impedance is:
• What is the ideal transformer turns-ratio equation relating primary and secondary voltages?
• What is a key difference between 9-lead and 12-lead motors in terms of configurability?
• Susceptance in AC circuits is defined as -1/X and has units of Siemens. Which statement is correct?
• In a split-phase motor, which winding is removed before reaching full speed?
• Which statement describes a dual-capacitor (capacitor-start capacitor-run) motor?
• How do you reverse a 3-phase induction motor?
• What provides the rotating magnetic field in an AC induction motor?
• Why is a squirrel‑cage rotor commonly called a cage rotor?
• Which statement properly describes RMS values and their use in power calculations?
• What is the effect of inserting a capacitor in series with a signal to create a high-pass filter?
• If the voltage across a capacitor doubles, by what factor does the stored energy change?
• Which statement about synchronous speed concept is true?
• In a typical induction motor, rotor speed is less than the synchronous speed due to slip.
• How do you compute the RMS value of a sine-wave voltage from its peak value?
• Increasing capacitance in a capacitor bank connected to a lagging inductive load primarily:
• Maintenance characteristics: AC motors vs DC motors.
• To increase starting torque in a split-phase motor, what is added in series with the start winding?
• If a motor has a service factor of 1.15 and is rated at 10 HP, what is the maximum continuous horsepower it can deliver under proper conditions?
• In a balanced three-phase system, what is the expression for the total apparent power S using line voltage and line current?
• For resistors of 4 Ω, 6 Ω, and 12 Ω connected in parallel to a 120 V source, what is the total current?
• For a three‑phase 60 Hz motor with 6 poles rotating at 1157 rpm, what is the percent slip?
• How does a rotating magnetic field work in an AC motor?
• What is a 12-lead AC motor?
• In AC circuit design, what is meant by conjugate matching for maximum power transfer?
• What is the Thevenin equivalent used for circuit analysis?
• Which formula does a wattmeter use to measure real power in AC circuits?
• Which of the following statements is correct regarding an AC induction motor?
• Which expression correctly describes the reflected impedance on the primary of an ideal transformer with turns ratio a?
• Leads on motor connection diagrams are numbered according to standard as what?
• Does the rotor of a synchronous motor rotate at synchronous speed?
• On a motor nameplate, what does HP stand for?
• What is the purpose of a voltage divider in a two-resistor circuit?
• What device is typically required to operate a PMAC motor?
• If the power factor is 0.8 leading, what does this indicate about the circuit?
• What is the typical slip percentage for a standard induction motor?
• A change from ABC phase sequence to ACB phase sequence will cause the motor to:
• An ideal transformer has turns ratio a = N_p/N_s. Which expression correctly gives the impedance seen at the primary when the secondary is loaded with Z_L?
• In a balanced wye-connected system, if the line-to-line voltage is 240 V, the line-to-neutral voltage is approximately which value?
• Which expression defines real power P in an AC circuit?
• What is the general expression for three-phase real power that is valid for both wye and delta configurations?
• Define impedance Z and its relation to resistance and reactance in AC circuits.
• What is the percent slip for an 8-pole, 60 Hz motor with a nameplate speed of 875 RPM?
• In a series circuit containing a resistor, inductor, and capacitor at resonance, what happens to the reactive part of the impedance?
• In AC circuit power calculations, what does cosφ represent?
• What is a phasor and why is it used in AC circuit analysis?
• Which of the following best describes the split-phase motor?
• Which statement is true about synchronous speed?
• In an ideal transformer with turns ratio Np:Ns = 2:1, which statement is correct?
• In a squirrel‑cage rotor, the end connections that short the rotor bars are called:
• On a motor nameplate, the "Frame" designation indicates what?
• If a 60 Hz, 4‑pole motor operates with a slip of 3%, what is the rotor speed?
• What is the synchronous speed for a 2‑pole, 60 Hz motor?
• How can you detect phase loss electrically at the motor terminals?
• What is the rotational speed of the stator's magnetic field called?
• Which NEMA design letter corresponds to high starting torque?
• What is a universal motor?
• Which expression gives the total reactive power for a balanced three-phase system using line voltage and current?
• In the parallel circuit across 12 V with 6 Ω and 3 Ω resistors, what is the current through the 3 Ω resistor?
• How would you determine the voltage across a resistor in a voltage divider with R1=2kΩ and R2=3kΩ across a 12 V source?
• Which statement best describes a typical high-voltage connection for a 9-lead motor?
• What is a 6-lead AC motor?
• What design feature helps reduce slot ripple in a squirrel cage rotor?
• What is the synchronous speed of a 3-phase, 60 Hz, 6-pole motor?
• What is the rotating speed of a three-phase 60 Hz 4-pole motor?
• Which expression correctly represents Vout in a simple two-resistor voltage divider with Vin across R1 and R2 in series and Vout across R2?
• In an unmarked 9-lead motor, which leads are the two ends of the same coil?
• How do you calculate the energy stored in a capacitor when the voltage across it is V?
• If frequency doubles, how does capacitive reactance XC change?
• What is the maximum power transfer condition in a DC circuit with a Thevenin source?
• Which statement best describes a capacitor-start induction-run motor?
• What is the impedance of a parallel LC circuit at resonance (assuming ideal components)?
• Why does swapping two leads reverse the motor?
• What is the synchronous speed of a 3-phase, 6-pole motor at 25 Hz?
• A 6-pole, 60 Hz motor runs at 1,140 RPM. What is its percent slip?
• A 4-pole, 60 Hz motor has synchronous speed of?
• For maximum power transfer in AC circuits, the load impedance should be the complex conjugate of the source impedance. Which equation expresses this?
• Which expression defines the net reactance X in a circuit containing inductive and capacitive elements?
• AC motors that use stators are called?
• In AC power calculations, what does the angle φ represent?
• In a series resonant circuit, increasing the Q factor has what effect on the bandwidth?
• In a 9-lead motor, which lead is connected to the tap on the T1-T4 coil?
• What do unbalanced resistance readings indicate?
• Thevenin's theorem allows you to replace a network with what two elements?
• Which statement correctly describes a capacitor-run (permanent split capacitor) motor?
• Which acronym does RMS stand for?
• In a series circuit with resistors 2 Ω, 5 Ω, and 7 Ω, what is the total resistance?
• Which expression correctly gives energy delivered to a resistor with constant voltage V across it for time t?
• In a parallel circuit with two resistors 6 Ω and 3 Ω connected to a 12 V source, what is the equivalent resistance?
• Which of the following statements applies to universal motors?
• What is capacitive reactance XC and how does it depend on frequency?
• What is the rotor speed for a 4‑pole, 60 Hz squirrel‑cage motor with a slip of 3.76%?
• If the phase sequence of a three‑phase induction motor is changed so that the opposite direction is produced, what is the most likely outcome?
• Why can't a 9-lead motor be reconfigured from wye to delta?
• How do you measure resistance across AC motor windings?
• What is the energy stored in an inductor and a capacitor, respectively?
• What is a 9-lead AC motor?
• Performance differences.
• What is the unit of conductance G?
• The Code Letter on a motor nameplate is used for what purpose?
• How is a 12-lead motor connected for low voltage wye (example 230 V)?
• If R = 8 Ω and X = 6 Ω, what is the magnitude of the impedance |Z|?
• Which of the following is a motor that can be run on both AC and DC?
• Speed control methods.
• What is inductive reactance XL and how does it depend on frequency?
• During phase loss, which of the following is a typical consequence?
• What is the power factor in relation to the phase angle φ in an AC circuit?
• When checking windings, why should resistance readings from each terminal to ground be infinite?
• How is impedance reflected from secondary to primary in an ideal transformer with turns ratio a = Np/Ns?
• The difference between synchronous speed and the rotor speed is called what?
• Which of the following expresses the total three-phase real power for a balanced system?
• Which statement correctly distinguishes capacitor-start induction-run motors from capacitor-run motors?
• In a series RLC circuit at resonance, which statement is true?
• In an AC circuit with sinusoidal voltage and current, how does instantaneous power p(t) differ from average power?
• What is the definition of phase loss (single-phasing)?
• Which statement is true about the rotor of a permanent magnet motor compared to the stator's field?
• What is a phasor diagram and how does it help analyze AC circuits with complex impedance?
• What does the light bulb test help identify?
• The stator's delta winding has a common connection between phases.
• How do you calculate the magnitude of impedance |Z| from R and X?