Related Topics

  Protection of Transformer  Equivalent Circuit diagram of single phase Transformer   Core type Transformer and Shell type Transformer  Transformer with winding Resistance and Magnetic Leakage  Transformer with winding Resistance but No Magnetic Leakage  Equivalent Resistance of single phase Transformer  Magnetic leakage of Single Phase Transformer  Oil Flow Indicator of the pump of Power Transformer  Silica Gel Breather of Transformer  Oil Pump of Transformer   Radiator of Transformer and working of Radiator  PRD of Transformer  MOG ( magnetic oil gauge ) of Transformer  Bushing of Transformer ( for H.V side and L.V side )  WTI and OTI of Transformer  Buchholz Relay of Transformer and Working of Buchholz Relay  Conservator tank of Transformer  What is a Power Transformer ?  Short Circuit Test or Full load Cu loss of Transformer   Open circuit test or No load Test of Transformer   Parallel operation of 3-phase Transformer  Earthing or Neutral Grounding Transformer   Transformer on On load Condition   What is a Transformer ?  E.m.f Equation of Transformer   Transformer on No load Condition

Index

SymbolsTransformerRelayPower-SystemBasic-electricalACSR-ConductorCircuit-BreakerInterview-questions-of-Basic-ElectricityInterview-questions-of-transformerInsulatorCurrent-TransformerMCQMCQ-powersystemThermal-power-stationInterview-questions-of-Power-SystemPower-ElectronicsInterview-questions-of-Underground-CableInterview-questions-of-IlluminationIlluminationMCQ-of-ElectronicsMCQ-of-Basic-ElectricalMCQ-of-Transformers MCQ-of-D.C-motor MCQ-of-D.C-generators

E.m.f Equation of Transformer

Suppose , N1 = No. of turns of primary coil &

N2 = No. of turns of secondary coil of a transformer.

Φm = Maximum flux in core ( webers)

= Bm x A

f= frequency of alternating current in Hz

From the figure , it has been seen that the flux Φ increases from its zero value to maximum value Φm in one quarter of the cycle i.e in 1/4 f second

=4 f Φm Wb/s or volt

Now, rate of change of flux per turn means induced e.m.f in volts.

∴ average e.m.f/ turn = 4 f Φm volt

If the magnitude of flux Φ varies sinusoidally, then the r.m.s value of induced e.m.f is obtained by multiplying the average value with from factor.

∴ r.m.s value of e.m.f./turn = 1.11 x 4fΦm = 4.44 fΦm volt

Now, r.m.s value of the induced e.m.f in the primary winding

∴ E1 = (induced e.m.f/turn) x No. of primary turns

∴ E1 = 4.44 f Φm N1 (As Φm = Bm x A )

E1 = 4.44 f N1Bm A .....................(i)

Similarly, r.m.s value of the e.m.f. induced in secondary is,

∴ E2 = (induced e.m.f/turn) x No. of Secondary turns

= 4.44 f Φm N2 (As Φm = Bm x A )

E2 = 4.44 f N2 Bm A .....................(ii)

It is seen from equation (i) and (ii) that E1 / N1 = E2 / N2 = 4.44 f Φm .

from the above equation it is seen that the e.m.f/ turn is the same in both primary and secondary windings.

.

Voltage Transformation Ratio :-

.

From equation (i) and (ii) ,we get

E1 / N1 = E2 / N2 = 4.44 f Φm = K

Constant K is known as voltage transformation ratio.

i) If N2 > N1 i.e K > 1,then transformer is called step-up transformer.

ii) If N2 < N1 i.e K < 1,then transformer is called step-down transformer.

<< Previous Next >> More details go to:
  • electrical4u.com
  • electricaleasy.com
  • Youtube.com
  • wikipedia.org
  • Related topics :



    Recent Post

    Multiple Choice Question (MCQ) of Electronics page-17:
    241. Which of the following statement is true? a) The saturation voltage VCF of silicon transistor is more than germanium transistor.
    b) The saturation voltage VCE for germanium transistor is more than silicon transistor.
    c) The saturation voltage VCE for silicon transistor is same as that for germanium.
    d) The saturation voltage VCE for silicon transistor is lower than germanium transistor.

    Read more...

    Multiple Choice Question (MCQ) of Electronics page-16:
    226. Which of the following statement is correct? a) Inner electrons are always present in the semiconductor.
    b) Bound electrons are always present in the semiconductor.
    c) Free electrons are always present in the semiconductor.
    d) Inner and bound electrons are always present in the semiconductor.

    Read more...

    Multiple Choice Question (MCQ) of Electronics page-15:
    211. The materials whose electrical conductivity is usually less than 1 × 106 mho/m are a) Semiconductors
    b) Conductors
    c) Insulators
    d) Alloys

    Read more...

    Multiple Choice Question (MCQ) of Electronics page-14:
    196. In which of the following device the base resistors are not added in the package but added externally? a) UJT
    b) CUJT
    c) PUT
    d) None of the above

    Read more...

    Multiple Choice Question (MCQ) of Electronics page-13:
    181. The conduction in JEFT is always by the a) Majority carriers
    b) Minority carriers
    c) Holes
    d) Electrons
    e) Holes and electrons simultaneously

    Read more...


    Name :   

    Comments: