WorksheetsM7: Review Questions (26307-20)
Total questions: 15
Worksheet time: 8mins
The three basic types of iron core transformers are _____.
dry, oil-filled, and auto
closed core, open core, and shell
control, power, and lighting
metal, nonmetallic, and high-temperature
If one of the transformers is damaged in a delta system, the configuration that may be used to temporarily carry the load is called a(n) _____
delta-wye configuration
delta-delta configuration
open delta configuration
center-tapped delta configuration
What causes voltage to be induced in a transformer?
Mutual induction
Reluctance
Capacitance
Transformer taps
The main purpose of a transformer is to _____
change the current
improve the power factor
change the output voltage
enter impedance into the circuit
When the field from one coil cuts through the turns of a second coil, _____
the second coil will not be affected
the coils will rotate
no current will flow in the circuit
voltage will be generated
The meter used to measure insulation resistance is called a(n) _____
ammeter
voltmeter
TTR
megger
Most control transformers are _____.
dry-type, step-down
oil-filled, step-up
dry-type, step-up
oil-filled, step-down
The three parts of a basic transformer are the _____.
housing, lifting hooks, and base
shell, open winding, and closed winding
primary winding, secondary winding, and core
dry, oil-filled, and gas-filled chambers
The power factor of a circuit can be improved by increasing the _____.
voltage
wire size
capacitance
current
In a transformer with a turns ration of 5:1 (the primary has five times the number of turns as the secondary), what will be the voltage on the secondary if the primary voltage is 120V?
48V
60V
12V
24V
The windings in an autotransformer _____
are isolated from one another
share part of a winding in common
constitute two separately derived systems
are rarely used in three-phase systems
One effect caused by magnetic leakage in transformers is a _____.
reactance voltage drop
lower secondary voltage
higher secondary voltage
low impedance
A dry-type transformer must be housed in a vault if rated at more than ______.
20kV
25kV
35kV
30kV
When AC flows through a transformer coil, the field generated around the coils is a _____
magnetic field
high-impedance field
non-magnetic field
rotating field
A symptom of a transformer with an open circuit is _____
no output on the secondary
excessive overheating
voltage drop across the secondary
high voltage on the secondary
