Question

The transformer core is laminated in order to

• A. minimize eddy current loss
• B. reduce copper loss
• C. reduce cost
• D. reduce hysteresis loss

Hint:

Different losses have different fixes:
Eddy current loss $\rightarrow$ Lamination
Hysteresis loss $\rightarrow$ Using soft iron core
Copper loss $\rightarrow$ Using thick wires

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
A transformer core experiences alternating magnetic fields, which induce circulating currents within the core material itself. These are called eddy currents and lead to energy lost as heat.
Step 2: Key Formula or Approach:
Recall the theoretical methods of reducing various losses in a transformer:
Lamination slices the solid metal core into thin insulated sheets.
Step 3: Detailed Explanation:
By building the core from thin insulated sheets (laminations) rather than a solid block, the conductive path for eddy currents is severely restricted.
The insulation prevents large macroscopic circular loops of current from forming. The smaller possible current loops experience higher resistance, significantly reducing the magnitude of the eddy currents and the corresponding \(I^2R\) heating loss.
Other options context:
- Copper loss is reduced using thicker wire.
- Hysteresis loss is reduced by using materials with narrow hysteresis loops (like soft iron).
Step 4: Final Answer:
Lamination minimizes eddy current loss.