Electrical Level 3 Transformers Questions with Correct Answers Rated A+

Electrical Level 3 Transformers Questions
with Correct Answers | Rated A+
A three phase four wire system that has the advantage of providing three phase power and
allowing lighting to be connected between any of the secondary phases and the neutral would
have a ? - CORRECT ANSWER -D.Wye secondary



What forces are always present in an AC circuit? - CORRECT ANSWER -Inductance and true
power



When voltage is stepped down in a transformer what happens to the current in the same
current? - CORRECT ANSWER -It is stepped up



What type of circuit uses the alternating magnetic field of one coil to generate voltage in a
second coil? - CORRECT ANSWER -...



Secondary voltage in a transformer can be increased or decreased by connecting various
- CORRECT ANSWER -Taps



Which winding of a transformer is connected to the load? - CORRECT ANSWER -Secondary



How can the need for additional KVAR's be reduced in large inductive loads with low power
factors? - CORRECT ANSWER -Installing capacitors



Which of the following best describes a transformer that increases the voltage on the primary
from 120v to 1200v on the secondary? - CORRECT ANSWER -A step up transformer



The installation of resistors and reactors is covered in ? - CORRECT ANSWER -NEC article
470

, What components are installed to increase the power factor and decrease the cost of electricity ca
X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2




used by large inductive loads? - CORRECT ANSWER -Capacitors
X2 X2 X2 X2 X2 X2 X2 X2




What type of transformer provides 120v between the center tapped terminal and each ungro u
X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2




nded terminal on either side and 240v across the full winding of each phase? -
X 2 X2 X2 X 2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2




CORRECT ANSWER -Delta-Delta X2 X2




Transformer cores support X2 X2 X2 - CORRECT ANSWER -Two windings
X2 X2 X2 X2




Capacitors are covered in X 2 X 2 X 2 X 2 - CORRECT ANSWER -NEC Article 460
X2 X2 X2 X2 X2




What type of transformer has primary circuits that have part of a winding in common? -
X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2




CORRECT ANSWER -...
X2 X2 X2




A lagging current for a motor or inductive device is represented by a power factor of
X2 X2 X2 X2 X2 X2 X2 X 2 X2 X2 X2 X2 X2 X 2 X2 X2




X ? - CORRECT ANSWER -Less than one
2 X 2 X 2 X 2 X2 X2 X2 X2




Which transformer is almost always required to be installed in a vault? - CORRECT ANSWER - Oil-
X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2




insulated



What type of transformers has more turns in the primary than the secondary? -
X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2




CORRECT ANSWER -Step down
X2 X2 X2 X2




Which section of the NEC contains transformer nameplate requirements? -
X2 X2 X2 X2 X2 X2 X2 X2 X2




CORRECT ANSWER -NEC Article 450.11
X2 X2 X2 X2 X2




To ensure maximum safety in a control transformer the secondary control circuit is
X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 X2 ?- X2




CORRECT ANSWER -Isolated from the primary circuit
X2 X2 X2 X2 X2 X2 X2