NYC ELECTRICIAN (DCAS) CIVIL SERVICE EXAM READY -
VERIFIED QUESTIONS AND ANSWERS - COMPREHENSIVE
LATEST VERSION
Q: What is the formula for Ohm's Law? ANSWER V = I x R (Voltage =
Current x Resistance)
Q: What unit measures electrical resistance? ANSWER Ohm (Ω)
Q: What unit measures electrical current? ANSWER Ampere (Amp)
Q: What unit measures electrical pressure or electromotive force?
ANSWER Volt (V)
Q: What unit measures electrical power? ANSWER Watt (W)
Q: What is the formula for Power? ANSWER P = V x I (Watts = Volts x
Amps)
Q: In a series circuit, what happens to the total resistance? ANSWER It
is the sum of all individual resistances.
Q: In a series circuit, is the current the same or different throughout?
ANSWER The current is exactly the same at all points.
Q: In a parallel circuit, what happens to the total resistance? ANSWER
It is always less than the smallest individual resistance.
Q: In a parallel circuit, is the voltage the same or different across each
branch? ANSWER The voltage is the same across all branches.
Q: What is the formula to find total current in a parallel circuit?
ANSWER It = I1 + I2 + I3 (Sum of the branch currents)
Q: What does DC stand for? ANSWER Direct Current
Q: What does AC stand for? ANSWER Alternating Current
Q: What type of current is produced by a battery? ANSWER Direct
Current (DC)
Q: What is the standard frequency of AC power in the US? ANSWER 60
Hertz (Hz)
,Q: What is the peak voltage of a 120V RMS AC circuit? ANSWER
Approximately 170 Volts (120 x 1.414)
Q: What does RMS stand for? ANSWER Root Mean Square
Q: What is another name for RMS voltage? ANSWER Effective voltage
Q: How are electrons flowing in a DC circuit? ANSWER From negative
to positive.
Q: What is conventional current flow? ANSWER From positive to
negative.
Q: What instrument measures voltage? ANSWER Voltmeter
Q: How is a voltmeter connected in a circuit? ANSWER In parallel
Q: What instrument measures current? ANSWER Ammeter
Q: How is an ammeter connected in a circuit? ANSWER In series
Q: What instrument measures resistance? ANSWER Ohmmeter
Q: What must be done before using an ohmmeter on a circuit? ANSWER
The circuit must be de-energized.
Q: What device combines a voltmeter, ammeter, and ohmmeter?
ANSWER Multimeter (VOM)
Q: What is a kilowatt-hour? ANSWER A unit of electrical energy equal
to 1,000 watts used for one hour.
Q: What does a transformer do? ANSWER It changes the voltage level
of an AC circuit.
Q: Can a transformer operate on DC? ANSWER No, it requires
alternating current to induce voltage.
Q: What is the difference between a step-up and step-down
transformer? ANSWER Step-up increases voltage; step-down
decreases voltage.
Q: If a transformer has a 2:1 ratio and the primary voltage is 240V, what
is the secondary voltage? ANSWER 120V
Q: What is inductance? ANSWER The property of a circuit that opposes
any change in current.
, Q: What is capacitance? ANSWER The ability of a component to store
an electrical charge.
Q: What does a capacitor do in a motor circuit? ANSWER It provides a
phase shift to help start the motor.
Q: What is impedance? ANSWER The total opposition to current flow in
an AC circuit (Resistance + Reactance).
Q: What is the symbol for current? ANSWER I
Q: What is the symbol for voltage? ANSWER E or V
Q: What is the symbol for power? ANSWER P or W
Q: What is the symbol for resistance? ANSWER R
Q: What are the three primary factors that affect resistance in a wire?
ANSWER Material, length, and cross-sectional area (gauge).
Q: As wire length increases, what happens to resistance? ANSWER It
increases.
Q: As wire gauge size increases (gets thicker), what happens to
resistance? ANSWER It decreases.
Q: What material is most commonly used for electrical conductors?
ANSWER Copper
Q: What material is most commonly used for electrical insulation?
ANSWER Rubber, plastic (THHN), or porcelain.
Q: What is a short circuit? ANSWER An unintended low-resistance
path that allows excessive current to flow.
Q: What is an open circuit? ANSWER A break in the circuit path that
stops current flow.
Q: What is a ground fault? ANSWER When current takes an unintended
path to ground.
Q: What is the formula for calculating the total resistance of two
resistors in parallel? ANSWER (R1 x R2) / (R1 + R2)
Q: What is the relationship between current and resistance in a circuit
with a fixed voltage? ANSWER They are inversely proportional (if R
goes up, I goes down).
VERIFIED QUESTIONS AND ANSWERS - COMPREHENSIVE
LATEST VERSION
Q: What is the formula for Ohm's Law? ANSWER V = I x R (Voltage =
Current x Resistance)
Q: What unit measures electrical resistance? ANSWER Ohm (Ω)
Q: What unit measures electrical current? ANSWER Ampere (Amp)
Q: What unit measures electrical pressure or electromotive force?
ANSWER Volt (V)
Q: What unit measures electrical power? ANSWER Watt (W)
Q: What is the formula for Power? ANSWER P = V x I (Watts = Volts x
Amps)
Q: In a series circuit, what happens to the total resistance? ANSWER It
is the sum of all individual resistances.
Q: In a series circuit, is the current the same or different throughout?
ANSWER The current is exactly the same at all points.
Q: In a parallel circuit, what happens to the total resistance? ANSWER
It is always less than the smallest individual resistance.
Q: In a parallel circuit, is the voltage the same or different across each
branch? ANSWER The voltage is the same across all branches.
Q: What is the formula to find total current in a parallel circuit?
ANSWER It = I1 + I2 + I3 (Sum of the branch currents)
Q: What does DC stand for? ANSWER Direct Current
Q: What does AC stand for? ANSWER Alternating Current
Q: What type of current is produced by a battery? ANSWER Direct
Current (DC)
Q: What is the standard frequency of AC power in the US? ANSWER 60
Hertz (Hz)
,Q: What is the peak voltage of a 120V RMS AC circuit? ANSWER
Approximately 170 Volts (120 x 1.414)
Q: What does RMS stand for? ANSWER Root Mean Square
Q: What is another name for RMS voltage? ANSWER Effective voltage
Q: How are electrons flowing in a DC circuit? ANSWER From negative
to positive.
Q: What is conventional current flow? ANSWER From positive to
negative.
Q: What instrument measures voltage? ANSWER Voltmeter
Q: How is a voltmeter connected in a circuit? ANSWER In parallel
Q: What instrument measures current? ANSWER Ammeter
Q: How is an ammeter connected in a circuit? ANSWER In series
Q: What instrument measures resistance? ANSWER Ohmmeter
Q: What must be done before using an ohmmeter on a circuit? ANSWER
The circuit must be de-energized.
Q: What device combines a voltmeter, ammeter, and ohmmeter?
ANSWER Multimeter (VOM)
Q: What is a kilowatt-hour? ANSWER A unit of electrical energy equal
to 1,000 watts used for one hour.
Q: What does a transformer do? ANSWER It changes the voltage level
of an AC circuit.
Q: Can a transformer operate on DC? ANSWER No, it requires
alternating current to induce voltage.
Q: What is the difference between a step-up and step-down
transformer? ANSWER Step-up increases voltage; step-down
decreases voltage.
Q: If a transformer has a 2:1 ratio and the primary voltage is 240V, what
is the secondary voltage? ANSWER 120V
Q: What is inductance? ANSWER The property of a circuit that opposes
any change in current.
, Q: What is capacitance? ANSWER The ability of a component to store
an electrical charge.
Q: What does a capacitor do in a motor circuit? ANSWER It provides a
phase shift to help start the motor.
Q: What is impedance? ANSWER The total opposition to current flow in
an AC circuit (Resistance + Reactance).
Q: What is the symbol for current? ANSWER I
Q: What is the symbol for voltage? ANSWER E or V
Q: What is the symbol for power? ANSWER P or W
Q: What is the symbol for resistance? ANSWER R
Q: What are the three primary factors that affect resistance in a wire?
ANSWER Material, length, and cross-sectional area (gauge).
Q: As wire length increases, what happens to resistance? ANSWER It
increases.
Q: As wire gauge size increases (gets thicker), what happens to
resistance? ANSWER It decreases.
Q: What material is most commonly used for electrical conductors?
ANSWER Copper
Q: What material is most commonly used for electrical insulation?
ANSWER Rubber, plastic (THHN), or porcelain.
Q: What is a short circuit? ANSWER An unintended low-resistance
path that allows excessive current to flow.
Q: What is an open circuit? ANSWER A break in the circuit path that
stops current flow.
Q: What is a ground fault? ANSWER When current takes an unintended
path to ground.
Q: What is the formula for calculating the total resistance of two
resistors in parallel? ANSWER (R1 x R2) / (R1 + R2)
Q: What is the relationship between current and resistance in a circuit
with a fixed voltage? ANSWER They are inversely proportional (if R
goes up, I goes down).
