Ch 14 Transformers Flashcards
Generally consists of 2 or more coils that are magnetically coupled on a common core
Transformer
There is mutual inductance between 2 magnetically coupled coils.
True
When current in one coil changes,
Voltage is induced in the other coil.
The primary is the winding connected to the source, and the secondary is the winding connected to the
Load
The number of turns in the primary winding and the number of turns in the secondary winding determines the
Turns ratio
The relative polarities of the primary and secondary voltages are determined by
The direction of the windings around the core.
A step-up transformer has a turns ration greater than 1.
True
A step-down transformer has a turns ratio less than 1.
True
A transformer cannot increase power.
True
In an ideal transformer, the power from the source (input power) is equal to the power delivered to the load (output power).
True
If the voltage is stepped up, the current is stepped down, and vice versa.
True
A load connected across the secondary winding of a transformer appears to the source as a reflected load having a value dependent on the reciprocal of the turns ratio squared.
True
An impedance-matching transformer can match a load resistance to an internal source resistance to achieve maximum power transfer to the load by selection of the proper turns ration.
True
A transformer does not respond to
Constant DC.
Conversion of electrical energy to heat in an actual transformer results from.
winding resistances
hysteresis loss in the core
eddy currents in the core
flux leakage
