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WorksheetsSEEU1002_2021-2_Chapter 5 (Transformer)
Total questions: 10
Worksheet time: 10mins
Transformer is __________ device.
an electromagnetic
an electromechanical
a magneto-electric
magnetic
an electrocardiograph
The function of a transformer is to ___________________.
raise or lower A.C. voltage
raise or lower apparent power
transfer A.C voltage
transfer A.C. current
create magnetic flux in the ferromagnetic core
Transformer transfer ____________ from one side to the other at the same ___________.
power, frequency
frequency, power
voltage, current
magnetic energy, core
heat, power
In its most basic form a transformer consists of ___________.
a ferromagnetic core, a primary winding and a secondary winding
a coil, a core and an enclosure
a power supply, a transformer and a load
an enclosure, a coil winding and a core
a primary winding and a secondary winding
The reason to use laminated iron core is to _______________.
reduce eddy current loss
reduce hysteresis loss
reduce magnetic flux leakage
increase flux density in the core
make the core stronger
The expanding and contracting magnetic field around the primary winding cuts the secondary winding and
induces an alternating voltage into the winding
transfer the voltage into the winding
transfer the current to the winding
causes the frequency to increase in the winding
causes the winding to vibrate
Air core transformers are used __________________.
when the voltage source has a high frequency above 20 kHz
when the voltage source has a low frequency below 20kHz
when the voltage source has a high power rating
when the current is very high
when the power to be transferred is very high
A step up transformer has the turn ratio _________________.
greater than one
less than one
equal to one
depends on the ratio of the primary voltage to the secondary voltage
depends on the ratio of the input apparent power to the output apparent power
Turn ratio of a transformer is
the ratio of the primary current to the secondary current
the ratio of the secondary current to the primary current
the ratio of the primary voltage to the secondary voltage
the ratio of the apparent power at the secondary side to the apparent power at the primary side
the ratio of the primary frequency to the secondary frequency
The core lose of a transformer is __________________.
the combination of Eddy current loss and the hysteresis loss
the combination of the copper loss and the iron loss
the loss caused by the losses in the primary and the secondary windings
the loss caused by the Eddy current loss
the loss caused by the hysteresis loss
