Class 4 (4th Engineer) MET 📅 Oct 2024

Exam Question

(a) Explain how fluorescent tubes power factor is improved. (6)

(b) A fluorescent lamp taking 80W at 0.7 power factor lagging from a 230v, 50-Hz supply is to be connected to unity power factor. Determine the value of the correcting approach required. (10)

Reference Answer

### (a) Explanation of Fluorescent Tube Power Factor Improvement (6 Marks)
Fluorescent tubes, by their inherent design, operate with a low lagging power factor. This is primarily due to the presence of an inductive ballast (choke) in their circuit. To achieve efficient and economical operation, the power factor of these circuits must be improved. This is typically achieved by connecting a suitable capacitor in parallel with the fluorescent tube circuit.
Here's a detailed explanation:
* **Cause of Low Power Factor**:

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