Basic Electrical Engineering Quiz

In a 3-phase star connected system, the current flowing through the line is ____

• Greater than the phase current

• Equal to the phase current

• Lesser than the phase current

• None of these

In a 3 - phase star connected load, the line voltage is equal to the ------

• 3 times the phase voltage

• √3 times the phase voltage

• 1/√3 times the phase voltage

• 1/3 times the phase voltage

An ideal transformer is one which has

• no losses and magnetic leakage

• interleaved primary and secondary windings

• a common core for its primary and secondary windings

• core of stainless steel and winding of pure copper metal

A transformer ________________

• Steps up or down dc voltages

• Changes ac to dc

• Steps up or down ac voltages

• Changes dc to ac

Transformer core are laminated in order to

• Reduce copper loss

• Minimize eddy current loss

• Reduce eddy current and hysteresis loss

• Reduce hysteresis loss

A transformer will work on __________

• ac supply only

• dc supply only

• ac as well as dc supply

• none of the above

A transformer transfers electrical energy from primary to secondary usually without a change in ____

• frequency

• power

• voltage

• time period

The voltage per turn of a primary of transformer is ________ the voltage per turn of the secondary

• the same as

• more than

• less than

• none of the above

The winding of the transformer with greater number of turns will be____________

• high voltage winding

• low voltage winding

• either high or low voltage winding

• none of the above

What is the advantage of using a three-phase system over a single-phase system?

• Higher efficiency

• Easier to maintain

• Smaller conductors for the same power

• All of the above