Permittivity concepts — assertion–reason Assertion (A): Relative permittivity εr of a material is determined by its atomic and molecular structure. Reason (R): Absolute permittivity ε0 is determined by the atomic structure of the material.

Introduction / Context:This question distinguishes the material-dependent relative permittivity εr from the universal constant ε0 (vacuum permittivity). It tests whether learners can identify which parameter reflects microstructure.

Given Data / Assumptions:

• Electrostatics in linear, homogeneous media.
• Relation ε = ε0 * εr.
• Atomic/molecular polarization mechanisms contribute to εr.

Concept / Approach:ε0 is a physical constant of vacuum and does not depend on any material. By contrast, εr depends on how bound charges in matter polarize under an applied field; it is set by electronic, ionic, and orientational polarizabilities governed by atomic and molecular structure. Therefore, A is true and R is false.

Step-by-Step Solution:Write ε = ε0 εr.Recognize ε0 as constant (property of free space).Connect εr to polarization P via P = ε0(εr − 1)E → material microstructure determines εr.

Verification / Alternative check:Clausius–Mossotti and Debye relations explicitly tie εr to number density and polarizability, confirming the material dependence of εr.

Why Other Options Are Wrong:(a) and (b) incorrectly attribute material dependence to ε0. (d) flips truth values. (e) denies the well-established facts.

Common Pitfalls:

• Confusing absolute and relative permittivity in formulas.
• Assuming ε0 can vary between media; it does not.

Final Answer:A is true but R is false