Missouri Valley Transformer Test UPDATED ACTUAL
Questions and CORRECT Answers
Resistance of current flow in a conductor Length, size and type of material
Magnetic lines of force Denser in air than in an iron core.
Metal core of transformer Concentrate the magnetic lines of flux
Requirements for current to flow through a winding Conductor, Complete Path, Difference of Potential
Principle of transformer operation Magnetic Induction
Primary winding Winding hooked to the source
Secondary winding Winding hooked to the load
Step Up transformer If the secondary voltage is higher than the primary voltage
Step Down transformer If the secondary voltage is lower than the primary voltage
Current value when voltage is stepped down Increases
Transformer efficiency Very efficient device.
Transformer polarity Labeled as either additive or subtractive
Current winding formula KVxI=A
Tap changer installation Installed in Primary winding
Operation of tap changer Can only be operated when it is in position
Not all transformers have a tap changing False
Turns and voltage ratio formula Primary Rating (Secondary Rating Current)
Voltage ratio of a transformer If the voltage ratio is 30:1, what is the current ratio? 1:30
Efficiency of an open bank 86.6%
Grounded delta secondary connection The lighter pot is the transformer with the largest 3
Ground references in an electrical system Can have multiple ground references
Questions and CORRECT Answers
Resistance of current flow in a conductor Length, size and type of material
Magnetic lines of force Denser in air than in an iron core.
Metal core of transformer Concentrate the magnetic lines of flux
Requirements for current to flow through a winding Conductor, Complete Path, Difference of Potential
Principle of transformer operation Magnetic Induction
Primary winding Winding hooked to the source
Secondary winding Winding hooked to the load
Step Up transformer If the secondary voltage is higher than the primary voltage
Step Down transformer If the secondary voltage is lower than the primary voltage
Current value when voltage is stepped down Increases
Transformer efficiency Very efficient device.
Transformer polarity Labeled as either additive or subtractive
Current winding formula KVxI=A
Tap changer installation Installed in Primary winding
Operation of tap changer Can only be operated when it is in position
Not all transformers have a tap changing False
Turns and voltage ratio formula Primary Rating (Secondary Rating Current)
Voltage ratio of a transformer If the voltage ratio is 30:1, what is the current ratio? 1:30
Efficiency of an open bank 86.6%
Grounded delta secondary connection The lighter pot is the transformer with the largest 3
Ground references in an electrical system Can have multiple ground references
