IEC (Independent Electrical Contractors) Year 2 –
Semester 2 Final Exam QUESTIONS AND VERIFIED
DETAILED ANSWERS |BRAND NEW!!
In a 60 Hertz system, the voltage will go to "0" ___ times
per second? - ANSWER-D.
120
When properly connected to deliver 208 volts from a 190-
volt supply circuit (affected by voltage drop), a ___ KVA
(standard size) 120 × 240 - 12/24-V transformer can
operate a 29 Amp load without being overloaded. -
ANSWER-B.
.75
,A ___ KVA 240 × 480 - 24/48-V transformer that is
connected to a 277-volt circuit should be used to operate a
230-volt 1Ø motor that draws 25 amps. - ANSWER-B.
1
Without being overloaded, a .5 KVA 120 x 240-12/24-V
transformer can carry a maximum of ___ amps at 12 volts.
- ANSWER-C.
41.6
Which connection diagram, shown in Figure 224.108,
should be used where the Supply Circuit is from a 1-pole
breaker 120/240-volt, 3-ph, 4-W panelboard? The load is
,rated to operate at 12 volts. The transformer is a 120 x
240 — 12/24 volt. - ANSWER-A.
I
Which connection diagram, shown in Figure 224.108,
should be used where the Supply Circuit is from a 2-pole
breaker 120/240-volt, 3-ph, 4-W panelboard? The load is
rated to operate at 12 volts. The transformer is a 120 x
240 — 12/24 volt. - ANSWER-D.
II
The circuit you have available to supply a 240-V, 150 A
load is 208 volts. The rating for a B-B transformer that can
, operate the load at its rated voltage is ___ KVA. -
ANSWER-C.
5.0
Refer to Figure 225.102. Panel K is 120/208V, 3Ø, 4-W.
The Control Panel requires 230 volts. Where the proper
connections are made and the input voltage is exactly 208
volts and a 120/240V-12/24V Group I transformer is used,
the calculated voltage that would be applied to the Control
Panel is ___ volts. - ANSWER-D.
229
Panel K, shown in Figure 225.102, is 120/240V, 3Ø, 4-W.
The Control Panel requires 208 volts. Using a 120/240V-
Semester 2 Final Exam QUESTIONS AND VERIFIED
DETAILED ANSWERS |BRAND NEW!!
In a 60 Hertz system, the voltage will go to "0" ___ times
per second? - ANSWER-D.
120
When properly connected to deliver 208 volts from a 190-
volt supply circuit (affected by voltage drop), a ___ KVA
(standard size) 120 × 240 - 12/24-V transformer can
operate a 29 Amp load without being overloaded. -
ANSWER-B.
.75
,A ___ KVA 240 × 480 - 24/48-V transformer that is
connected to a 277-volt circuit should be used to operate a
230-volt 1Ø motor that draws 25 amps. - ANSWER-B.
1
Without being overloaded, a .5 KVA 120 x 240-12/24-V
transformer can carry a maximum of ___ amps at 12 volts.
- ANSWER-C.
41.6
Which connection diagram, shown in Figure 224.108,
should be used where the Supply Circuit is from a 1-pole
breaker 120/240-volt, 3-ph, 4-W panelboard? The load is
,rated to operate at 12 volts. The transformer is a 120 x
240 — 12/24 volt. - ANSWER-A.
I
Which connection diagram, shown in Figure 224.108,
should be used where the Supply Circuit is from a 2-pole
breaker 120/240-volt, 3-ph, 4-W panelboard? The load is
rated to operate at 12 volts. The transformer is a 120 x
240 — 12/24 volt. - ANSWER-D.
II
The circuit you have available to supply a 240-V, 150 A
load is 208 volts. The rating for a B-B transformer that can
, operate the load at its rated voltage is ___ KVA. -
ANSWER-C.
5.0
Refer to Figure 225.102. Panel K is 120/208V, 3Ø, 4-W.
The Control Panel requires 230 volts. Where the proper
connections are made and the input voltage is exactly 208
volts and a 120/240V-12/24V Group I transformer is used,
the calculated voltage that would be applied to the Control
Panel is ___ volts. - ANSWER-D.
229
Panel K, shown in Figure 225.102, is 120/240V, 3Ø, 4-W.
The Control Panel requires 208 volts. Using a 120/240V-
