TRANSFORMER

[Audio] Hi everyone Today our topic is transformer.

[Audio] TRANSFORMER IS THE DEVICE WHICH IS USED TO STEP UP AND STEP DOWN THE APPLIED VOLTAGE. A DEVICE USED TO TRANSFORM ELECTRICAL POWER FROM ONE VOLTAGE AND CURRENT LEVEL TO ANOTHER..

[Audio] THERE ARE THREE MAIN PARTS OF TRANSFORMER. PRIMARY COIL SECONDARY COIL LAMINATED IRON CORE.

[Audio] IT WORKS ON THE PRINCIPLE OF MUTUAL INDUCTION. Which states that THE RATE OF CHANGE OF FLUX IN PRIMARY COIL INDUCED AN EMF IN SECONDARY COIL..

[Audio] CURRENT PASSING THROUGH PRIMARY COIL CREATES A MAGNETIC FIELD. THE PRIMARY AND SECONDARY COIL ARE WRAPPED AROUND A CORE OF HIGH MAGNETIC PERMEABILITY, SUCH AS IRON SO THAT MOST OF MAGNETIC FLUX PASSING THROUGH THE SECONDARY COIL..

[Audio] THE CHANGING FLUX IN PRIMARY COIL INDUCED EMF IN SECONDARY COIL ACCORDING TO FARADAY LAW OF ELECTROMAGNETIC INDUCTION "THE EMF INDUCED IN THE CIRCUIT IS PROPORTIONAL TO RATE OF CHANGE OF FLUX.".

[Audio] The voltage across secondary coil is given by faraday law which states that Voltage across secondary coil equal to change of flux and number of turns of secondary coil Similarly the voltage across primary coil is given by Voltage across primary coil equal to number of turns of primary coil and rate of change of flux Taking the ratio of these two equations we get The ratio of voltage across secondary to coil to primary coil equal to Ratio of number of turns of secondary coil to primary coil.

[Audio] WHEN NUMBER OF TURNS OF SECONDARY COIL IS GREATER THEN PRIMARY COIL IS CALLED STEP UP TRANSFORMER. WHEN NUMBER OF TURNS OF PRIMARY COIL IS GREATER THEN SECONDARY COIL IS CALLED STEP DOWN TRANSFORMER.

[Audio] THE AMOUNT OF ENERGY CANNOT BE STEPPED UP AND DOWN. THE EFFICIENCY OF IDEAL TRANSFORMER is 100%. THE PRODUCT OF VOLTAGE AND CURRENT IS CONSTANT. SO PRODUCT OF VOLTAGE AND CURRENT ACROSS SECONDARY COIL EQUAL TO PRODUCT OF VOLTAGE AND CURRENT ACROSS PRIMARY COIL THE RATIO OF VOLTAGE ACROSS SECONDARY AND PRIMARY COIL EQUAL TO RATIO OF CURRENT ACROSS PRIMARY COIL TO SECONDARY COIL IT FOLLOWS THAT IF THE VOLTAGE IS STEPPED UP THE CURRENT IS STEPPED DOWN AND VICE VERSA..

[Audio] TRANSFORMER CORES ARE MADE OF LAMINATED IRON THAT IS MANY THIN SHEETS OF IRON PRESSED TOGETHER BUT SEPARATED BY THIN INSULATING LAYERS. THIS LIMIT THE CIRCULATION OF AN EDDY CURRENT TO THE THICKNESS OF ONE LAMINA, RATHER THAN WHOLE CORE THUS REDUCING THE OVERALL HEATING EFFECT.

[Audio] GRID STATIONS, ELECTRICITY IN DIFFERENT LEVELS ARE USED. HERE TRANSFORMERS CHANGE THE HIGH VOLTAGE ELECTRICITY BACK INTO THE LOW LEVEL ELECTRICITY. TRANSFORMERS ENABLE EFFICIENT LONG DISTANCE HIGH VOLTAGE TRANSMISSION OF ELECTRICAL ENERGY..

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