Question

Match the following.

(i) Hysteresis loss,

(a) Can be reduced by constructing the core with laminated sheets of the alloy steel

(ii) Eddy current loss,

(b) Can be reduced by the use of special high grades of alloy steel as core material.

Short answer

1. The correct match for (i) is (b).
2. The correct match for (ii) is (a).

Step-by-step solution

Define the iron losses in transformer.

In transformer, there are losses such as iron/core losses, copper/ohmic losses, stray losses and dielectric losses.

The iron losses are further categorized as hysteresis losses and eddy current losses.

${\mathbf{P}}_{\mathbf{i}}\mathbf{=}{\mathbf{P}}_{\mathbf{e}}\mathbf{+}{\mathbf{P}}_{\mathbf{h}}$ ……. (1)

Here, $P_i$is iron loss, $P_e$is eddy current loss and $P_h$is hysteresis loss.

Explanation for minimizing the eddy current loss.

To reduce the eddy current loss $P_e$in a transformer, the laminated sheets are used in a core using steel alloy and then it is stamped. The thickness of this laminations is in millimeter. But, it should not be much thin, otherwise the lamination may breakdown.

Explanation for minimizing the hysteresis loss.

To reduce the hysteresis loss $P_h$in a transformer, the laminated sheets cannot be used, because hysteresis loss is more related to the magnetic material.

To reduce the hysteresis loss, the special high grade alloy steel must be used.

Therefore, the correct match for (i) is (b) and the correct match for (ii) is (a).