Among the following dielectric materials commonly used in capacitors (air, paper, mica, oil), which one typically exhibits the highest dielectric strength?

Introduction:
Dielectric strength is the maximum electric field a material can withstand without electrical breakdown. Selecting a dielectric with high strength enables compact capacitors that tolerate higher voltages safely.

Given Data / Assumptions:

• Materials considered: air, paper, mica, and oil.
• Typical comparative values are referenced qualitatively (exact values vary by purity and thickness).

Concept / Approach:
Typical dielectric strength ranking among the listed materials places mica at the top, followed by paper/oil (depending on formulation), with air lowest. Mica’s crystalline structure and low defect density contribute to its high breakdown field.

Step-by-Step Solution:
Air: low dielectric strength (on the order of a few kV/mm).Oil and paper: moderate; improved compared to air, used in power capacitors and insulation systems.Mica: high dielectric strength, often an order of magnitude above air, enabling thin, high-voltage capacitors.

Verification / Alternative check:
Historical and modern mica capacitors are favored where stability and high breakdown performance are needed (e.g., RF and precision circuits), corroborating its superior dielectric strength among the choices.

Why Other Options Are Wrong:

• Air: Lowest strength; breakdown occurs at relatively small fields.
• Paper: Better than air but lower than mica.
• Oil: Useful for cooling and insulation, but typical strength below mica.
• Ceramic (reference): Not part of the answer set; included to contextualize materials.

Common Pitfalls:

• Assuming oil always surpasses solids; purity and gap geometry matter.
• Confusing dielectric constant (permittivity) with dielectric strength.

Final Answer:
Mica