ESCO Electrical Test – Latest Exam Prep
2025/2026 | Practice Questions & Study Guide
What is current flow? - correct answerD.The flow of electrons in a circuit
What is impedance? - correct answerA.Opposition to alternating current
Like charges will - correct answerB.Repel each other
Any material that will readily release electrons is called: - correct answerB.A conductor
The symbol for current is: - correct answerB. I
Electricity can produce: - correct answerD. All the above
light
heat
magnetism
The safety ground conductor is usually colored: - correct answerB.Green
An electron has: - correct answerB.A negative charge
Which of the following materials would be best suited for use as a semi-conductor? -
correct answerD.Silicon
Which of the following meters must use internal power to check a load or circuit? -
correct answerA.Ohmmeter
What would be the result if a 24 volt, 20 ohm contactor coil was wired in series with a 24
volt, 200 ohm control relay? - correct answerB.Only the control relay would operate
Three defrost heaters, each 15 ohms, are wired in parallel to a 120 volt power supply.
How many Watts are consumed? - correct answerC. 2880
When testing a capacitor with an analog or digital ohmmeter, the meter should: - correct
answerB.Measure low resistance then return to a high reading
How much resistance must be placed in a 120 volt circuit to limit the current to 2 amps?
- correct answerA.60 ohms
What is resistance? - correct answerA.Opposition to electron flow
,In electrical wiring, a black colored wire indicates: - correct answerA. A hot conductor
How many watts are used by a heater operating on 460 volts and drawing 5 amps? -
correct answerD .2300
How are fuses sized? - correct answerD .Both A and B
What is generally considered the maximum allowable supply voltage variation - correct
answerA.5%
Capacitors are rated in: - correct answerD .Both B and C
What is the term used to describe the output side of a transformer? - correct answerD
.Secondary side
One horsepower is equal to ______ watts. - correct answerB. 746
A parallel circuit contains an 18 ohm and a 9 ohm resistor. What is the total resistance?
- correct answerA.6 ohms
In a series circuit, the voltage drop across each load will: - correct answerD .Add up to
equal the source voltage
Which of the following is equal to 2.1kW? - correct answerc .2100 watts
A capacitor analyzer is designed to check: - correct answerD .The capacitance of the a
capacitor
On an electronic oil safety switch, what changes the pressure signal to an electrical
signal? - correct answerA.Transducer
A three phase load requires a minimum of - correct answerA.Three supply lines
An electronically commutated motor (ECM) is designed to: - correct answerD .Provide
proper airflow under various conditions
Resistance can be calculated by: - correct answerA.E divided by I
The total resistance in a parallel circuit will be: - correct answerD .Less than the
smallest resistance
Which of the following statements about current is true? - correct answerB.Current flow
will increase when voltage increases
, When resistors are wired parallel: - correct answerB.The voltage drop across each
resistor will be the same as the applied source voltage
Which of the following is equal to 100 milliamps? - correct answerC. 0.10 amps
The meter on a house measures the ____ passing through it. - correct answerC. Watts
What is the correct formula for determining wattage? - correct answerA.W = E x I
A parallel circuit consists of three resistors; R1 = 30 ohms, R2 = 15 ohms, R3 = 10
ohms. If the current through R2 = 4 amps, what is the source voltage? - correct
answerB.60 volts
Three 300 ohm resistors are wired parallel. What is the total resistance? - correct
answerA.100 ohms
Amps can be calculated by: - correct answerA. E/R
B.W/E
C.The square root of W/R
answer: D. all the above
Voltage can be calculated by: - correct answerC.IxR
An ohmmeter should never be connected to a: - correct answerD. Charged capacitor
until it has been discharged
Which of the following would be considered an inductive load? - correct answerD.
Electric motor
The voltage to ground of a high leg or "stinger leg" on a three phase open delta system
will be approximately: - correct answerC. 208
Which of the following is the symbol for impedance? - correct answerD. Z
What amperage measurement would you expect if you clamped your meter around both
wires in a two wire circuit? - correct answerA.0 due to the cancellation of the two
magnetic fields
A diode is used to? - correct answerA. Control the direction of electron flow
Three resistors are wired parallel. Two have a value of 12 ohms, one of 6. What is the
total resistance? - correct answerC. 3
A transformer has 1000 turns on the primary side and 500 on the secondary. What is
the output if the input is 120v? - correct answerC. 60v
2025/2026 | Practice Questions & Study Guide
What is current flow? - correct answerD.The flow of electrons in a circuit
What is impedance? - correct answerA.Opposition to alternating current
Like charges will - correct answerB.Repel each other
Any material that will readily release electrons is called: - correct answerB.A conductor
The symbol for current is: - correct answerB. I
Electricity can produce: - correct answerD. All the above
light
heat
magnetism
The safety ground conductor is usually colored: - correct answerB.Green
An electron has: - correct answerB.A negative charge
Which of the following materials would be best suited for use as a semi-conductor? -
correct answerD.Silicon
Which of the following meters must use internal power to check a load or circuit? -
correct answerA.Ohmmeter
What would be the result if a 24 volt, 20 ohm contactor coil was wired in series with a 24
volt, 200 ohm control relay? - correct answerB.Only the control relay would operate
Three defrost heaters, each 15 ohms, are wired in parallel to a 120 volt power supply.
How many Watts are consumed? - correct answerC. 2880
When testing a capacitor with an analog or digital ohmmeter, the meter should: - correct
answerB.Measure low resistance then return to a high reading
How much resistance must be placed in a 120 volt circuit to limit the current to 2 amps?
- correct answerA.60 ohms
What is resistance? - correct answerA.Opposition to electron flow
,In electrical wiring, a black colored wire indicates: - correct answerA. A hot conductor
How many watts are used by a heater operating on 460 volts and drawing 5 amps? -
correct answerD .2300
How are fuses sized? - correct answerD .Both A and B
What is generally considered the maximum allowable supply voltage variation - correct
answerA.5%
Capacitors are rated in: - correct answerD .Both B and C
What is the term used to describe the output side of a transformer? - correct answerD
.Secondary side
One horsepower is equal to ______ watts. - correct answerB. 746
A parallel circuit contains an 18 ohm and a 9 ohm resistor. What is the total resistance?
- correct answerA.6 ohms
In a series circuit, the voltage drop across each load will: - correct answerD .Add up to
equal the source voltage
Which of the following is equal to 2.1kW? - correct answerc .2100 watts
A capacitor analyzer is designed to check: - correct answerD .The capacitance of the a
capacitor
On an electronic oil safety switch, what changes the pressure signal to an electrical
signal? - correct answerA.Transducer
A three phase load requires a minimum of - correct answerA.Three supply lines
An electronically commutated motor (ECM) is designed to: - correct answerD .Provide
proper airflow under various conditions
Resistance can be calculated by: - correct answerA.E divided by I
The total resistance in a parallel circuit will be: - correct answerD .Less than the
smallest resistance
Which of the following statements about current is true? - correct answerB.Current flow
will increase when voltage increases
, When resistors are wired parallel: - correct answerB.The voltage drop across each
resistor will be the same as the applied source voltage
Which of the following is equal to 100 milliamps? - correct answerC. 0.10 amps
The meter on a house measures the ____ passing through it. - correct answerC. Watts
What is the correct formula for determining wattage? - correct answerA.W = E x I
A parallel circuit consists of three resistors; R1 = 30 ohms, R2 = 15 ohms, R3 = 10
ohms. If the current through R2 = 4 amps, what is the source voltage? - correct
answerB.60 volts
Three 300 ohm resistors are wired parallel. What is the total resistance? - correct
answerA.100 ohms
Amps can be calculated by: - correct answerA. E/R
B.W/E
C.The square root of W/R
answer: D. all the above
Voltage can be calculated by: - correct answerC.IxR
An ohmmeter should never be connected to a: - correct answerD. Charged capacitor
until it has been discharged
Which of the following would be considered an inductive load? - correct answerD.
Electric motor
The voltage to ground of a high leg or "stinger leg" on a three phase open delta system
will be approximately: - correct answerC. 208
Which of the following is the symbol for impedance? - correct answerD. Z
What amperage measurement would you expect if you clamped your meter around both
wires in a two wire circuit? - correct answerA.0 due to the cancellation of the two
magnetic fields
A diode is used to? - correct answerA. Control the direction of electron flow
Three resistors are wired parallel. Two have a value of 12 ohms, one of 6. What is the
total resistance? - correct answerC. 3
A transformer has 1000 turns on the primary side and 500 on the secondary. What is
the output if the input is 120v? - correct answerC. 60v
