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Chemistry · 2026 · 2 marks
CBSE 2026 · Region 5 · Set 3 · Q18
(a) Name the cell used in hearing aids and watches. (b) Define conductivity. Why is direct current (DC) not used for the measurement of resistance of…
(a)
Name the cell used in hearing aids and watches.
(b)
Define conductivity. Why is direct current (DC) not used for the measurement of resistance of an ionic solution? []
Marking-scheme solution
(a)
Mercury cell /Button cell
(b)
The conductivity of a solution at any given concentration is the conductance of one
unit volume of solution kept between two platinum electrodes with unit area of cross
DC changes the composition of the solution.
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CBSE Class 12 Chemistry past-paper question from the 2026 board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.