Match List-I with List-II
| List-I | List-II |
| Physical quantity | Unit |
| (A) Electric flux | (I) \( \mathrm{V\,m^{-1}} \) |
| (B) Polarisation | (II) \( \mathrm{kg\,m^{-1}\,s^{-2}} \) |
| (C) Electric field | (III) \( \mathrm{V\,m} \) |
| (D) Energy density | (IV) \( \mathrm{C\,m^{-2}} \) |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → (A) - (III), (B) - (IV), (C) - (I), (D) - (II)
Each unit follows from the defining relation of the quantity.
(A) Electric flux — this matches (III) V m. Flux is field times area, \( \Phi = EA \), so its unit is \( \mathrm{V\,m^{-1}} \times \mathrm{m^{2}} = \mathrm{V\,m} \).
(B) Polarisation — this matches (IV) C m−2. Polarisation is the dipole moment per unit volume, so its unit is \( \mathrm{C\,m}/\mathrm{m^{3}} = \mathrm{C\,m^{-2}} \).
(C) Electric field — this matches (I) V m−1. From \( E = V/d \), the field is potential difference per unit distance.
(D) Energy density — this matches (II) kg m−1 s−2. It is energy per unit volume, \( \mathrm{J\,m^{-3}} \), and \( \mathrm{J} = \mathrm{kg\,m^{2}\,s^{-2}} \), so the unit is \( \mathrm{kg\,m^{-1}\,s^{-2}} \).