HV Exit Exam • Set 7 Question 18 of 30
As the mechanical contact clamping force between two closed electrical contacts is increased, the contact resistance will:
✓
Direct Answer
Option D: Decrease due to increased microscopic contact area
Increasing mechanical contact pressure crushes microscopic surface asperities and breaks surface oxide films, increasing the true metallic contact area and reducing contact resistance.
All Options
A
Increase linearly
B
Increase exponentially
C
Remain completely unaltered
D
Decrease due to increased microscopic contact area
(Correct Answer)
Detailed Explanation & Context
Increasing mechanical contact pressure crushes microscopic surface asperities and breaks surface oxide films, increasing the true metallic contact area and reducing contact resistance.
Relevant Framework: STCW 2010 Manila Amendments • DG Shipping E-Learning & Exit Exam Standards • High Voltage Safety Officer & Switchgear Operations (HV).
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