Units for intrinsic dielectric strength In high-voltage engineering, the intrinsic dielectric strength (breakdown strength) of an insulating medium is quantified in which units?

Introduction / Context:
Intrinsic dielectric strength characterizes the maximum electric field a material can withstand without electrical breakdown. The unit must represent electric field intensity, not merely voltage or current.

Given Data / Assumptions:

• Dielectric strength refers to breakdown threshold of E-field.
• Common reporting in kV/mm or kV/cm or kV/m depending on context.
• SI base unit for field: V/m.

Concept / Approach:

Electric field E is potential gradient: E = V / d with units of V/m. Intrinsic strength is a limiting value of E. Therefore, appropriate engineering units are kV/mm, kV/cm, or kV/m. Among the choices, kV/m is the correct dimension for electric field intensity.

Step-by-Step Reasoning:

Verification / Alternative check:

Material data sheets list breakdown strengths (e.g., air ≈ 3 kV/mm under standard conditions), confirming field-based units.

Why Other Options Are Wrong:

• kV or V: voltage alone lacks length scale; does not represent field.
• A or A/m: current or magnetizing field units, not electric field.

Common Pitfalls:

Confusing breakdown voltage (depends on geometry) with intrinsic breakdown field (material property normalized by distance).

Final Answer:

kV/m