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- Subject
- Transformerselectrical-engineering-mcqs › transformers
- Published
- 28 Jun 2018
- Last updated
- 28 May 2026
Explanation
The humming sound in transformers predominantly arises due to magnetostriction, a phenomenon where the core material changes shape slightly when magnetized, causing vibrations and noise. Load changes, oil, and mechanical vibrations may influence the noise but are not the main cause.
More Transformers MCQs
Practice related questions from the same subject.
- 1.Identify the incorrect statement about an ideal single-phase transformer with a turns ratio of 1:2, which draws 10 A from a 200 V AC source.
- 2.In a transformer operating at a fixed voltage, which losses stay constant regardless of variations in load?
- 3.Which type of losses are present in rotating electrical machines but are absent in transformers?
- 4.How does the eddy current loss change when the frequency of a fixed applied voltage is increased?
- 5.Why are approximately 10% of the end turns in a power or distribution transformer heavily insulated?
- 6.Which type of transformer core construction results in reduced core losses and enhanced permeability?
- 7.What is the common term for the sound generated by a transformer?
- 8.Which component of a transformer can be seen externally?
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