The physical quantity, which is dimensionally equivalent to the ratio of capacitance to distance, is
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Dielectric permittivity
The capacitance of a parallel plate capacitor is
\( \displaystyle C = \frac{\varepsilon A}{d} \)
Dividing by a distance d:
\( \displaystyle \frac{C}{d} = \varepsilon\,\frac{A}{d^{2}} \)
Here \( A/d^{2} \) is an area divided by a length squared, which is dimensionless. So C/d has the same dimensions as the permittivity \( \varepsilon \). The units agree: permittivity is measured in \( \mathrm{F\,m^{-1}} \), which is farad per metre.