The transformer transforms a) voltage b) current c) power d) frequency e) all of the above

Transformer basically transforms voltage, but there are current transformer too.

Transformer does not effect frequency and power, both remains the same.

However frequency is one major factor in designing of transformer.

A transformer is a static machine used for transforming power from one circuit to another without changing frequency. This is a very basic definition of transformer.

 

 

History of Transformer

 

The history of transformer was commenced in the year1880. In the year1950,400KV electrical power transformer was introduced in highvoltage electrical power system. In the early1970s, unit rating as large as1100MVA was produced and800KV and even higher KV class transformers were manufactured in year of1980.

 

Use of Power Transformer

 

Generation of electrical power in lowvoltage level is very much cost effective. Hence electrical power is generated in lowvoltage level. Theoretically, this lowvoltage level power can be transmitted to the receiving end. But if the voltage level of a power is increased, the current of the power is reduced which causes reduction in ohmic or I2R losses in the system, reduction in cross sectional area of ​​the conductor ie reduction in capital cost of the system and it also improves thevoltage regulation of the system. Because of these, low level power must be stepped up for efficient electrical power transmission. This is done by step up transformer at the sending side of the power system network. As this highvoltage power may not be distributed to the consumers directly, this must be stepped down to the desired level at the receiving end with the help of step down transformer. These are the uses ofelectrical power transformer in theelectrical power system.

 

Two winding transformers are generally used where ratio between high voltageand low voltage is greater than2. It is cost effective to use auto transformer where the ratio between high voltage and lowvoltage is less than2. Again three phase single unit transformer is more cost effective than a bank of three single phase transformer unit in a three phase system. But still it is preferable to use than the later where power dealing is very large since such large size of three phase single unit power transformer may not be easily transported from manufacturer's place to work site.

 

 

Types of Transformer

 

Transformers can be categorized in different ways, depending upon their purpose, use, construction etc. The types of transformer are as follows,

 

Step Up Transformer & Step Down Transformer - Generally used for stepping up and down the voltagelevel of power in transmission and distribution power network.Three Phase Transformer & Single Phase Transformer - Former is generally used in three phase power system as it is cost effective than later but when size matters, it is preferable to use bank of three single phase transformer as it is easier to transport three single phase unit separately than one single three phase unit.

 

 

 

Electrical Power Transformer, Distribution Transformer & Instrument Transformer - Transformer is generally used in transmission network which is normally known as power transformer, distribution transformer is used in distribution network and this is lower rating transformer and current transformer & potential transformer, we use for relay and protection purpose inelectrical power system and in different instruments in industries are called instrument transformer.Two Winding Transformer & Auto Transformer - Former is generally used where ratio between highvoltage and low voltage is greater than2. It is cost effective to use later where the ratio between highvoltage and low voltage is less than2.Outdoor Transformer & Indoor Transformer - Transformers that are designed for installing at outdoor are outdoor transformers and transformers designed for installing at indoor are indoor transformers.

"C" power

Current

Voltage transformers transform only the voltage 

Current transformers transform only the current 

 

 

it's voltage

I agree with

Jafar Indian Zain Saqqaf

A transformer transforms one level of voltage and current into another. A step up transformer raises voltage and lowers current, usually to make long power lines more efficient, and a step down transformer raises current and lowers voltage, usually to make it safe for homes and appliances. 

A) Voltage is the correct answer 

B) Currency is a correct answer 110 V to220 V or in reverse (120 to440 V)

C) Power is an other name for electricity ... technically it is a correct answer 

D) Frequency no it does not change the frequency US110/120 V60 Hertz and Europe220/230 V with50 Hertz ... the transformer converts the Voltage, but not the Hertz cycles ... biggest difference is that a motor runs faster or slower depending what Hertz your motor has ... it will run, however ware and tear is a negative result

E) therefore is not a  correct  answer

A transformer can do all things . According to applications wise we can use different types of tranaformers. Ex : if v/t transformers can step up &step down voltage levels(i,e it is called as potential transformers also in core system to measure voltage).similalrly c/t transformers also use to according to our usage If you want generate frequeny in high level then the frequency transfomers . So qns is clear to under that according our requirement we can use which type transformer is prefferable for used in electrical wise and power electronics wise

Tranformer tranforms only voltage keeoing frequency constant.. They are power transformers.. Which are either Step up transformer or step down tranformee

C. Power

The transformer transforms voltage and current, but not the frequency and the power as the frequency and power remains constant in the process of transformation but power deteriorate due to losses in the transformation process