(a)
If the primary coil is connected to an A.C source, the A.C passing through the coil sets up a changing ternating magnetic flux in the soft iron core. The secondary coil is linked with the changing flux which Juces an e.m.f in it. Since the number of turns in a secondary is less than that in the primary, the induced e.m.f is less than e.m.f in the primary. For s reason the A.C output is less than the A.0 in primary.
(b)(i) Ways in which heat is lost in a transformer:
- Eddy current
- Flux leakages
- Hysteresis losses
- Copper or joules losses
(ii)
Losses | Minimizing method |
Eddy current losses. Flux leakage,Hysteresis losses.Copper or joules losses. | Laminating the core.Design an efficient core.Core made of soft magnetic material of soft iron.Using low resistance coil. |
(c) (i) \(\frac{N_s}{N_p} = \frac{E_s}{E_p} = \frac{220}{4400}\)
\(N_p : N_s = 20 : 1\)
(ii) Efficiency = \frac{output}{input} = \frac{V_s \times I_s}{V_p \times I_p}\)
= \(\frac{95}{100} = \frac{60}{4400 \times I_p}\)
\(I_p = \frac{100 \times 60}{95 \times 440} = 0.014A\)