CFESA ELECTRICAL EXAM UPDATED
QUESTIONS WITH VERIFIED ANSWERS
2026/2027 LATEST UPDATE
What is the accepted maximum voltage difference between the name plate
voltage and the supplied voltage? - CORRECT ANSWER>>>>+ or -
10%
What is the voltage between any two hot lines of a 230 volt delta power
supply? - CORRECT ANSWER>>>>230V
what is the voltage between a hot line and ground on a 240 volt delta
power supply - CORRECT ANSWER>>>>No usable voltage
what is the voltage between any two hot lines of a 230 volt grounded delta
power supply -
CORRECT ANSWER>>>>230V
draw a diagram of a 230 volt grounded delta power supply. label all of the
voltages and the wild
leg - CORRECT ANSWER>>>>
what is the wild leg? - CORRECT ANSWER>>>>leg with higher than
120v to ground or neutral
Page 1 of 80
,what danger is the wild leg? - CORRECT ANSWER>>>>high voltage
that will damage 120v component in the circuit
what is the voltage between either of the non wild leg hot lines and neutral
in a 230 volt grounded delta system? - CORRECT ANSWER>>>>115v
how do you determine which hot line is the wild leg in a 250 volt
grounded delta power supply? - CORRECT ANSWER>>>>the one that
does not measure 120 volts to neutral or ground
what danger is there when replacing a three phase circuit breaker in a
230 volt grounded delta power supply? - CORRECT
ANSWER>>>>crossing the hot lines and supplying the wild leg to the
wrong terminal in the unit.
Why is a "WYE" power supply so versatile - CORRECT
ANSWER>>>>can get 120v and 208v as well as single and three phase
What is the voltage between any two hot lines in a 208 volt WYE power
supply? - CORRECT
ANSWER>>>>208v
What is the voltage between any hot line and neutral or ground in a 208
volt WYE power supply? - CORRECT ANSWER>>>>120v
What is the voltage from any hot line to ground or neutral, on a 480 volt
WYE power supply? - CORRECT ANSWER>>>>277v
,What do the following prefixes mean? Micro,Kilo,Mega,Milli -
CORRECT
ANSWER>>>>1/1,000,000, 1000, 1,000,000, 1/1000
If you know the wattage and voltage, how do you determine the current?
- CORRECT ANSWER>>>>Divide the wattage by the voltage
If you know the voltage and current how do you determine the wattage?
- CORRECT ANSWER>>>>Multiply voltage times current
If a circuit is supplied with 100 volts and the total resistance of the circuit
is 200 ohms, how much current will the circuit draw? - CORRECT
ANSWER>>>>.5 amps
If a piece of equipment is supplied 208 volts and the amp meter clamped
to the hot line reads 20 amps, what is the wattage of the load? -
CORRECT ANSWER>>>>4160 Watts
How much voltage is in one hot line? - CORRECT ANSWER>>>>None
What happens to current in a parallel circuit? - CORRECT
ANSWER>>>>It divides across resistances
what happens to voltage across the loads in a parallel circuit? -
CORRECT ANSWER>>>>stays the same
what happens to the voltage across the loads in a series circuit? -
CORRECT ANSWER>>>>it divides across the resistances
Page 3 of 80
, what happens to the current in a series circuit? - CORRECT
ANSWER>>>>It stays the same everywhere
in a parallel circuit the total resistance of the circuit will always be less
than what resistance? - CORRECT ANSWER>>>>the smallest
resistance
how do you find the total resistance of a series circuit? - CORRECT
ANSWER>>>>add the resistances together
how do you find the total resistance of a parallel circuit? - CORRECT
ANSWER>>>>1/RT = 1 /R1 + 1/R2 + 1/R3 ...
If a circuit is wired parallel, and the supply voltage is 120 volts, each load
must be rated at what voltage? - CORRECT ANSWER>>>>120 volts
if a circuit has two elements wired in series, and each is rated at 120 volts,
what voltage must be
supplied to the circuit in order for the elements to heat at full power? -
CORRECT ANSWER>>>>240 volts
What is the advantage of using higher voltages? - CORRECT
ANSWER>>>>Lower Current and wire size
QUESTIONS WITH VERIFIED ANSWERS
2026/2027 LATEST UPDATE
What is the accepted maximum voltage difference between the name plate
voltage and the supplied voltage? - CORRECT ANSWER>>>>+ or -
10%
What is the voltage between any two hot lines of a 230 volt delta power
supply? - CORRECT ANSWER>>>>230V
what is the voltage between a hot line and ground on a 240 volt delta
power supply - CORRECT ANSWER>>>>No usable voltage
what is the voltage between any two hot lines of a 230 volt grounded delta
power supply -
CORRECT ANSWER>>>>230V
draw a diagram of a 230 volt grounded delta power supply. label all of the
voltages and the wild
leg - CORRECT ANSWER>>>>
what is the wild leg? - CORRECT ANSWER>>>>leg with higher than
120v to ground or neutral
Page 1 of 80
,what danger is the wild leg? - CORRECT ANSWER>>>>high voltage
that will damage 120v component in the circuit
what is the voltage between either of the non wild leg hot lines and neutral
in a 230 volt grounded delta system? - CORRECT ANSWER>>>>115v
how do you determine which hot line is the wild leg in a 250 volt
grounded delta power supply? - CORRECT ANSWER>>>>the one that
does not measure 120 volts to neutral or ground
what danger is there when replacing a three phase circuit breaker in a
230 volt grounded delta power supply? - CORRECT
ANSWER>>>>crossing the hot lines and supplying the wild leg to the
wrong terminal in the unit.
Why is a "WYE" power supply so versatile - CORRECT
ANSWER>>>>can get 120v and 208v as well as single and three phase
What is the voltage between any two hot lines in a 208 volt WYE power
supply? - CORRECT
ANSWER>>>>208v
What is the voltage between any hot line and neutral or ground in a 208
volt WYE power supply? - CORRECT ANSWER>>>>120v
What is the voltage from any hot line to ground or neutral, on a 480 volt
WYE power supply? - CORRECT ANSWER>>>>277v
,What do the following prefixes mean? Micro,Kilo,Mega,Milli -
CORRECT
ANSWER>>>>1/1,000,000, 1000, 1,000,000, 1/1000
If you know the wattage and voltage, how do you determine the current?
- CORRECT ANSWER>>>>Divide the wattage by the voltage
If you know the voltage and current how do you determine the wattage?
- CORRECT ANSWER>>>>Multiply voltage times current
If a circuit is supplied with 100 volts and the total resistance of the circuit
is 200 ohms, how much current will the circuit draw? - CORRECT
ANSWER>>>>.5 amps
If a piece of equipment is supplied 208 volts and the amp meter clamped
to the hot line reads 20 amps, what is the wattage of the load? -
CORRECT ANSWER>>>>4160 Watts
How much voltage is in one hot line? - CORRECT ANSWER>>>>None
What happens to current in a parallel circuit? - CORRECT
ANSWER>>>>It divides across resistances
what happens to voltage across the loads in a parallel circuit? -
CORRECT ANSWER>>>>stays the same
what happens to the voltage across the loads in a series circuit? -
CORRECT ANSWER>>>>it divides across the resistances
Page 3 of 80
, what happens to the current in a series circuit? - CORRECT
ANSWER>>>>It stays the same everywhere
in a parallel circuit the total resistance of the circuit will always be less
than what resistance? - CORRECT ANSWER>>>>the smallest
resistance
how do you find the total resistance of a series circuit? - CORRECT
ANSWER>>>>add the resistances together
how do you find the total resistance of a parallel circuit? - CORRECT
ANSWER>>>>1/RT = 1 /R1 + 1/R2 + 1/R3 ...
If a circuit is wired parallel, and the supply voltage is 120 volts, each load
must be rated at what voltage? - CORRECT ANSWER>>>>120 volts
if a circuit has two elements wired in series, and each is rated at 120 volts,
what voltage must be
supplied to the circuit in order for the elements to heat at full power? -
CORRECT ANSWER>>>>240 volts
What is the advantage of using higher voltages? - CORRECT
ANSWER>>>>Lower Current and wire size
