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SarkariResultOutAdditional Assistant Engineer (Electrical) · 2026

Previous Year Question

Which of the following factors increases corona power loss?
  1. Decreasing the conductor radius
  2. Increasing the air density factor
  3. Decreasing the phase voltage
  4. Decreasing the supply frequency

Correct answer: A

Explanation

A smaller conductor radius increases the electric field intensity at the conductor surface, making corona inception easier and increasing corona loss. Higher air density generally raises disruptive voltage, while lower voltage or lower frequency tends to reduce loss.

Step-by-step solution

Factors Affecting Corona Loss explanatory diagram

Correct Answer

A — Decreasing the conductor radius

Explanation

A smaller conductor radius increases the electric field intensity at the conductor surface, making corona inception easier and increasing corona loss. Higher air density generally raises disruptive voltage, while lower voltage or lower frequency tends to reduce loss.

Key Concept

Factors Affecting Corona Loss

Exam Point

Corona worsens with smaller radius, higher voltage and higher frequency.

Exam tip

Corona worsens with smaller radius, higher voltage and higher frequency.

Quick method

Corona worsens with smaller radius, higher voltage and higher frequency.