Transformer works on the principle of mutual induction. It consists of two coils insulated from each other. They are wounded on soft iron core either one on one or on separate limbs.
When an alternating voltage is applied to primary, the resulting current produces a magnetic flux, in secondary and induces e-m-f in it. In ideal primary has negligible resistance and all flux linked to is transferred to B.
Since current and potential are inversely related
we get \(\frac {V_s}{V_p}=\frac {N_s}{N_p}=\frac {i_p}{i_s}\)
It Ns > Np it is called step-up transformer. I & Np > Ns is called step down voltage.
