Testbank: PE Electrical and Computer – Power Exam Study Guide (2nd Ed – Wasim Asghar) | 600+ Practice Problems & Full-Length Exam PDF

PE Electrical and Computer – Power
Exam Study Guide (2nd Edition – Wasim
Asghar) | Complete Prep Book with
Practice Problems PDF

2. Select the information below that is not required to be on a motor nameplate

according to the 2017 National Electrical Code®.

(A) Rated full load motor speed.

(B) Continuous or time rating.

(C) Rated heater voltage if applicable.

(D) None of the above. - answer-D



3. Calculate the average DC voltage output to the nearest volt of a single-phase, 120V

RMS 60 Hz full wave rectifier circuit made up of four insulated gate bipolar

transistors if the gate of each pair of transistors are sent a pulse width signal that

begins at 0.926 ms and ends at 7.41 ms for each period of the rectified voltage that

the pair is associated with.

(A) 87

(B) 102

(C) 114

(D) 130 - answer-B




1

,4. Select the minimum size copper 90 degree Celsius rated conductor run in conduit

that is permitted to provide power to a three-phase, 60 Hz, 208 Volt, 60 HP,

continuous duty, NEMA D induction motor according to the 2017 National Electrical

Code®.

(A) 2/0 AWG

(B) 3/0 AWG

(C) 4/0 AWG

(D) 250 kcmil - answer-C



5. Select the most accurate description below of how arc fault circuit interrupters

operate for the application of residential protection.

(A) Arc fault circuit interrupters protect residential circuits by de-energizing the

branch circuit when the difference between the current on the hot and neutral

conductor is greater than approximately zero amps.

(B) Arc fault circuit interrupters protect residential circuits by de-energizing the

branch circuit anytime a circuit overload occurs that could potentially lead to a

fire.

(C) Arc fault circuit interrupters protect residential circuits by de-energizing the

branch circuit when any amount of arcing is detected.

(D) Arc fault circuit interrupters protect residential circuits by de-energizing the

branch circuit when a dangerous level of arcing is detected. - answer-D



6. Select the answer below that best describes the change in trip characteristics of an

ANSI #51 relay after the time current characteristic curve has been changed to a



2

, more time inverse curve type compared to before. Assume no other changes have

been made.

(A) The relay will operate faster at higher pick up levels.

(B) The relay will operate slower at higher pick up levels.

(C) The time characteristic curve will shift in the positive vertical direction on the

time axis.

(D) None of the above. - answer-A



7. A square metal junction box is needed for the following: a single yoke three-way light

switch with three 12 AWG conductors, and a 12 AWG uninsulated ground wire

terminated on the switch held in place by a cable clamp inside the box, one 12 AWG

and 14 AWG conductor spliced together inside the box, and one 12 AWG conductor

that passes through the box. Select the minimum box size that may be used

according to the 2017 National Electrical Code® if all conductors originate outside

the box.

(A) 4 × 2 1⁄2 inch

(B) 4 × 2 1⁄8 inch

(C) 4 11⁄16 × 1 1⁄4 inch

(D) 4 11⁄16 × 1 1⁄2 inch - answer-C



8. A three-phase delta connected power source delivers power to a 10+j8.2Ω

three-phase delta connected load through a 0.47+jΩ line impedance. Calculate the

magnitude of the delta phase voltage of the power source to the nearest volt if the

current circulating in the A phase of the delta source is 55A<-17°. The entire system



3