ELE Review – Questions With Accurate Solutions
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Terms in this set (369)
"What do the following prefixes mean: a.1/1,000,000
a. Micro b. 1000 times
b. Kilo c. 1,000,000 times
c. Mega d. 1/1000
d. Milli
If you know the wattage and voltage, Divide the wattage by the voltage
how do you determine the current?
If you know the voltage and current, Multiply the voltage times the current
how do you determine the wattage?
If a circut is supplied with 100 volts 1/2 amp
and the total resistance of the circut is
200 ohms, how much current will the
circuit draw?
If a piece of equipment is supplied 208 * 20 = 4160
208 volts and the ammeter clamped
to the hot line reads 20 amps, what is
the wattage of the load?
How much voltage is in one hot line? None. Voltage is the potential difference between
two different lines
What happens to current in a parallel It divides into the different loads
circuit?
What happens to the voltage across It stays the same
the loads in a parallel circuit?
,What happens to the voltage across It divides across the loads
the loads in a series circuit?
What happens to the current in a It stays the same throughout the series circuit
series circuit?
In a parallel circuit the total resistance The lowest resistance in the circuit
of the circuit wil always be less than
what resistance?
How do you find the total resistance Add up the individual resistances
of a series circuit?
How do you find the total resistance 1 = 1 + 1 + 1 + .....
of a parallel circuit? ----
Rt R1 R2 R3
If a circuit is wired parallel, and the 120 volts
supply voltage is 120 volts, each load
must be rated at what voltage?
If a circut has two elements wired in 120 X 2 = 240 volts
series and each is rated at 120 volts,
what voltage must be supplied to the
circutin order for the elements to heat
at full power?
What is the advantage of using higher Lower currents and smaller wire size requirements
voltages?
Is there a negative and positive line in No. Hots and neutral
AC power supplies?
What is the voltage between two hot 230 V
lines in a 230-volt system?
What is the voltage between two hot 208 V
lines in a 208-volt system?
,What is the voltage between a hot line 115 V
and a neutral in a 230-volt phase
supply?
What is the voltage between a hot line 115 V
and a neutral in a 208-volt phase
supply?
What is the accepted maximum Plus or minus 10%
voltage difference between the name
plate voltage and the supplied
voltage?
What is the voltage between any two 230 V
hot lines of a 230 volt Delta power
supply?
What is the voltage between a hot line No usable voltage
and ground on a 250 volt Delta power
supply?
What is the voltage between any two 230 V
hot lines of a 230 volt Grounded Delta
power supply?
Draw a diagram of a 230 volt
Grounded Delta power supply. LAbel
all of the voltages and the wild leg
What is the wild leg? A hot leg not directly connected to the center
tapped winding with a very high potential voltage to
ground or
neutral
What danger is presented by a wild The high voltage will damage the control circut if
leg? connected to a 120 volt control circuit on a 120/230
volt
machine
, What is the voltage between either of 115 V
the non wild leg hot lines and neutral
in a 230-volt Grounded Delta system?
What is the voltage between the wild Unknown, but will be a high voltage
leg and neutral or ground on a 250-
volt power supply?
How do you determine which hot line Check each hot line to neutral. Two will read 115 volts,
is the wild leg in a 250 volt Grounded and one will read a high voltage. The leg with the
Delta power supply? high voltage reading to neutral or ground is the wild
leg
What danger is there when replacing a Must be careful not to cross the wiring on the
three phase circuit breaker in a 230 breaker which will change the wiring connection that
volt Grounded Delta power supply? the wild
leg is connected to and may damage the equipment
Why is a ""Wye"" power supply so Can get 208 V single and three phase as well as 115 V
versatile? all from the one power suply
What is the voltage between any two 208 V
hot lines in 208 volt Wye power
supply?
What is the voltage between any hot 115 V
line and neutral or ground in a 208
volt Wye power supply?
What is the voltage from any hotline 277 V
to ground or neutral, on a 480 volt
Wye power supply?
Save
Terms in this set (369)
"What do the following prefixes mean: a.1/1,000,000
a. Micro b. 1000 times
b. Kilo c. 1,000,000 times
c. Mega d. 1/1000
d. Milli
If you know the wattage and voltage, Divide the wattage by the voltage
how do you determine the current?
If you know the voltage and current, Multiply the voltage times the current
how do you determine the wattage?
If a circut is supplied with 100 volts 1/2 amp
and the total resistance of the circut is
200 ohms, how much current will the
circuit draw?
If a piece of equipment is supplied 208 * 20 = 4160
208 volts and the ammeter clamped
to the hot line reads 20 amps, what is
the wattage of the load?
How much voltage is in one hot line? None. Voltage is the potential difference between
two different lines
What happens to current in a parallel It divides into the different loads
circuit?
What happens to the voltage across It stays the same
the loads in a parallel circuit?
,What happens to the voltage across It divides across the loads
the loads in a series circuit?
What happens to the current in a It stays the same throughout the series circuit
series circuit?
In a parallel circuit the total resistance The lowest resistance in the circuit
of the circuit wil always be less than
what resistance?
How do you find the total resistance Add up the individual resistances
of a series circuit?
How do you find the total resistance 1 = 1 + 1 + 1 + .....
of a parallel circuit? ----
Rt R1 R2 R3
If a circuit is wired parallel, and the 120 volts
supply voltage is 120 volts, each load
must be rated at what voltage?
If a circut has two elements wired in 120 X 2 = 240 volts
series and each is rated at 120 volts,
what voltage must be supplied to the
circutin order for the elements to heat
at full power?
What is the advantage of using higher Lower currents and smaller wire size requirements
voltages?
Is there a negative and positive line in No. Hots and neutral
AC power supplies?
What is the voltage between two hot 230 V
lines in a 230-volt system?
What is the voltage between two hot 208 V
lines in a 208-volt system?
,What is the voltage between a hot line 115 V
and a neutral in a 230-volt phase
supply?
What is the voltage between a hot line 115 V
and a neutral in a 208-volt phase
supply?
What is the accepted maximum Plus or minus 10%
voltage difference between the name
plate voltage and the supplied
voltage?
What is the voltage between any two 230 V
hot lines of a 230 volt Delta power
supply?
What is the voltage between a hot line No usable voltage
and ground on a 250 volt Delta power
supply?
What is the voltage between any two 230 V
hot lines of a 230 volt Grounded Delta
power supply?
Draw a diagram of a 230 volt
Grounded Delta power supply. LAbel
all of the voltages and the wild leg
What is the wild leg? A hot leg not directly connected to the center
tapped winding with a very high potential voltage to
ground or
neutral
What danger is presented by a wild The high voltage will damage the control circut if
leg? connected to a 120 volt control circuit on a 120/230
volt
machine
, What is the voltage between either of 115 V
the non wild leg hot lines and neutral
in a 230-volt Grounded Delta system?
What is the voltage between the wild Unknown, but will be a high voltage
leg and neutral or ground on a 250-
volt power supply?
How do you determine which hot line Check each hot line to neutral. Two will read 115 volts,
is the wild leg in a 250 volt Grounded and one will read a high voltage. The leg with the
Delta power supply? high voltage reading to neutral or ground is the wild
leg
What danger is there when replacing a Must be careful not to cross the wiring on the
three phase circuit breaker in a 230 breaker which will change the wiring connection that
volt Grounded Delta power supply? the wild
leg is connected to and may damage the equipment
Why is a ""Wye"" power supply so Can get 208 V single and three phase as well as 115 V
versatile? all from the one power suply
What is the voltage between any two 208 V
hot lines in 208 volt Wye power
supply?
What is the voltage between any hot 115 V
line and neutral or ground in a 208
volt Wye power supply?
What is the voltage from any hotline 277 V
to ground or neutral, on a 480 volt
Wye power supply?
