Math, asked by nancyinsan2938, 1 year ago

A step-down transformer is employed to reduce the main supply of 220 v to 11 v. the primary draws 5 a of current and the secondary draws 90 a of current. what is the efficiency of the transformer?

Answers

Answered by Eviltwin
22
Power = V * I 
                      where , V is the voltage 
                                   I is current.
The main supply is called the primary and the other is Secondary.

In the step down transformer , 
                                                Voltage at primary = 220 v
                                                current at primary = 5 A

Hence , Input power = 220 * 5 = 1100 W

   Voltage at secondary = 11 V
   current at secondary = 90 A
Hence output power = 11 * 90 = 990 W

Efficiency of a transformer = ((Output Power)/(Input Power ) ) * 100 
Note ; This gives the efficiency in percentage and usually the answer is expressed in percentage only.

There fore , efficiency = (990/1100)*100 = 90
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