Match List-I with List-II
|
List-I |
List-II |
|
Materials |
Conductivity \( (S m)^{-1} \) |
|
(A) Gold |
\( \text{(I) }1.0\times10^{-16} \) |
|
(B) Germanium |
\( \text{(II) }1.2\times10 \) |
|
(C) Glass |
\( \text{(III) }4.5\times10^3 \) |
|
(D) Graphite |
\( \text{(IV) }2.0 \) |
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)
Materials are classed by the size of their electrical conductivity. Conductors (metals, and graphite among non-metals) have very large conductivity, semiconductors have intermediate values, and insulators such as glass have extremely small conductivity.
(A) Gold — This matches (III) \(4.5\times10^3\). Gold is a metal with free electrons, so it has the largest of the four values.
(B) Germanium — This matches (IV) 2.0. Germanium is a semiconductor, so its conductivity lies between those of conductors and insulators.
(C) Glass — This matches (I) \(1.0\times10^{-16}\). Glass is an insulator; it has almost no mobile charge carriers.
(D) Graphite — This matches (II) \(1.2\times10\). Graphite conducts through the delocalised electrons in its layers; its conductivity is high but lower than that of metals.
Shortcut: The insulator glass must take the smallest value, \( 10^{-16} \), so (C)-(I); only Option (4) has it.
NCERT (2026-27 edition):
Conductance of Electrolytic Solutions – …
