Match List - I with List - II.
| List - I | List - II | ||
| (A) | Mobility | (I) | \( \Omega\,\mathrm{m} \) |
| (B) | Current density | (II) | \( \mathrm{A\,m^{-2}} \) |
| (C) | Conductivity | (III) | \( \Omega^{-1}\,\mathrm{m^{-1}} \) |
| (D) | Resistivity | (IV) | \( \mathrm{m^{2}\,V^{-1}\,s^{-1}} \) |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → (A)-(IV), (B)-(II), (C)-(III), (D)-(I)
The SI unit of each quantity follows from its defining relation.
(A) Mobility — this matches (IV) \( \mathrm{m^{2}\,V^{-1}\,s^{-1}} \). Mobility is drift velocity per unit electric field, \( \mu = v_d/E \), so its unit is \( (\mathrm{m\,s^{-1}})/(\mathrm{V\,m^{-1}}) \).
(B) Current density — this matches (II) \( \mathrm{A\,m^{-2}} \). Current density is current per unit area, \( j = I/A \).
(C) Conductivity — this matches (III) \( \Omega^{-1}\,\mathrm{m^{-1}} \). Conductivity is the reciprocal of resistivity, \( \sigma = 1/\rho \), so its unit is the reciprocal of \( \Omega\,\mathrm{m} \).
(D) Resistivity — this matches (I) \( \Omega\,\mathrm{m} \). From \( R = \rho l/A \), \( \rho = RA/l \), with unit \( \Omega \times \mathrm{m^{2}}/\mathrm{m} \).
Note: A similar question was also asked in CUET (UG) 2025 on 03-06-2025 (Slot 2).
NCERT (2026-27):
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