Match List-I with List-II
|
List-I (Property) |
List-II (Symbol) |
|
(A) Resistance |
(I) \( κ \) |
|
(B) Specific resistance |
(II) \( Λ_m \) |
|
(C) molar conductivity |
(III) \( R \) |
|
(D) specific conductance |
(IV) \( ρ \) |
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)-(II), (D)-(I)
The resistance of a conductor is proportional to its length l and inversely proportional to its area of cross section A. The constant of proportionality is the resistivity; its reciprocal is the conductivity, and the conductivity per unit concentration is the molar conductivity:
\( \displaystyle R = \rho\,\frac{l}{A} \qquad \kappa = \frac{1}{\rho} \qquad \Lambda_m = \frac{\kappa}{c} \)
(A) Resistance — This matches (III) \(R\). It is measured in ohm (\( \Omega \)).
(B) Specific resistance — This matches (IV) \(ρ\). Specific resistance is the older name of resistivity, the resistance of a conductor 1 m long and 1 m2 in cross section; unit \( \Omega\,\mathrm{m} \).
(C) molar conductivity — This matches (II) \(Λ_m\). It is the conductivity divided by the molar concentration; unit \( \mathrm{S\,m^2\,mol^{-1}} \).
(D) specific conductance — This matches (I) \(κ\). Specific conductance is the older name of conductivity, the reciprocal of resistivity; unit \( \mathrm{S\,m^{-1}} \).
Shortcut: (A)-(III) appears in Options (2) and (4); (C)-(II) then leaves only Option (2).
NCERT (2026-27 edition):
Conductance of Electrolytic Solutions – “… The constant of proportionality, ρ (Greek, rho), is called resistivity (specific resistance). Its SI units are ohm metre (Ω m) and quite often its submultiple, ohm centimetre (Ω cm) is also used. … The inverse of resistivity, called conductivity (specific conductance) is represented by the symbol, κ (Greek, kappa).”