Match List-I with List-II
| List-I | List-II |
| Physical Quantity | Unit |
| (A) Current Density | (I) N m C-1 |
| (B) Mobility of Charges | (II) V m A-1 |
| (C) Electromotive force | (III) V Ω-1 m-2 |
| (D) Resistivity | (IV) m2 V-1s-1 |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → (A) - (III), (B) - (IV), (C) - (I), (D) - (II)
Write each quantity from its defining relation and express its SI unit in the form given in List-II.
(A) Current Density — this matches (III) V Ω-1 m-2. Current density is current per unit area, \( j = I/A \), in A m−2, and \( 1\,\mathrm{A} = 1\,\mathrm{V\,\Omega^{-1}} \) (from Ohm’s law).
(B) Mobility of Charges — this matches (IV) m2 V-1s-1. Mobility is drift velocity per unit field, \( \mu = v_d/E \), in (m s−1)/(V m−1) = m2 V−1 s−1.
(C) Electromotive force — this matches (I) N m C-1. Emf is work done per unit charge, in J C−1, and \( 1\,\mathrm{J} = 1\,\mathrm{N\,m} \).
(D) Resistivity — this matches (II) V m A-1. From \( \rho = RA/l \), the unit is \( \Omega\,\mathrm{m} \), and \( 1\,\Omega = 1\,\mathrm{V\,A^{-1}} \).