.................. is a static device that changes electric voltage from one level to another without change of frequency.

Transformer operates on ac supply only

In transformer operation, the primary and secondary windings are connected to each other electricity

In transformer , the core is made up of thin laminated sheets to reduce

Core-type transformers are popular in high voltage applications like distribution transformers, power transformers, and auto transformers

Shell-type transformers are popular in low voltage applications (single phase transformers) like transformers used in electronic circuits and power electronic converters

The windings of Transformer are made

.............. the winding to which the input voltage is applied

These are the winding to which the output voltage is applied

In High voltage winding , The conductor used will be thinner than that of the low voltage winding.

In Low voltage winding ,the winding. is made of thick copper conductors

In Low voltage winding ,the winding. is made of thick copper conductors Because :

Insulating paper , cardboard and Transformer oil are used in Transformer as

The Single phase voltage in Bahrain is

Efficiency (η) Law state that

Line voltage for star connection is equal to :

Line voltage for Delta connection is equal to :

Line Current for Delta connection is equal to :

Line Current for Star connection is equal to :

It is used to sense faults occurring inside the transformer.

are used to cool the transformer oil.

controls the moisture level in the transformer.

is used to expel boiling oil in the transformer during heavy internal faults in order to avoid the explosion of the transformer.

conserves the transformer oil.

In a balanced Star-connected three-phase system , The neutral current is :

The primary and secondary windings of the transformer are linked by

How is the voltage transformer connected with the load?

How is the Current transformer connected with the load?

The useful power or the true power dissipated in an AC system is called

The power which is not consumed; but stored in the system is

is the product of the load voltage and load current.

In a balanced Delta connected three-phase system , The neutral current is :

One of the following is not a cooling methods of three-phase transformer :

A Star-star (Y-Y) three-phase transformer has Np = 6500 turns VLine-primary = 11 kV and VLine-secondary = 415 V. What is the primary phase voltage?

A Star- delta (Y-Δ) three-phase transformer has a primary Line voltage of 415V and a secondary line voltage of 1500 v. If the primary turns is 1200 turns, calculate the secondary turns (Ns).

In an ideal three-phase transformer with a transformer ratio of 15 , what is the input power if the output power is 1000 w