Dielectric comparison: Among air, mica, glass, and paper, identify the capacitor dielectric with the highest typical dielectric constant.

Introduction / Context:
Dielectric materials determine a capacitor’s capacitance for a given geometry. A higher dielectric constant (relative permittivity) allows more charge storage at the same voltage, enabling physically smaller capacitors for the same value.

Given Data / Assumptions:

• Dielectrics listed: air, mica, glass, paper.
• Compare typical relative permittivity ranges used in general-purpose capacitors.

Concept / Approach:
Relative permittivity (epsilon_r) indicates how much the dielectric increases capacitance compared to vacuum. Typical values: air ~ 1, paper ~ 2–3, mica ~ 5–7, many glasses ~ 5–10 (and specialized glasses even higher).

Step-by-Step Solution:
Identify approximate ranges: air ≈ 1paper ≈ 2–3mica ≈ 5–7glass ≈ 5–10 (or higher depending on composition)Highest among given standard choices is glass.

Verification / Alternative check:
Reference component data sheets: general-purpose glass dielectrics often outpace mica and paper in epsilon_r, explaining compact high-value glass capacitors and feedthrough designs.

Why Other Options Are Wrong:

• air: Lowest epsilon_r (~1), used mainly where minimal dielectric loading is desired.
• mica: Stable and low-loss, but typical epsilon_r below common glasses.
• paper: Lower epsilon_r than mica and glass.

Common Pitfalls:
Confusing dielectric constant with breakdown voltage or loss tangent. A higher dielectric constant does not automatically mean better for all applications; losses and stability also matter.

Final Answer:
glass