Question

why are few drops of Dil. H2 S o4 added to water​

Answer 1

few drops of H2So4 added to water to make it electrolytic solutions

Answer 2

this is catalysis process.

in this, the water is acidified using dil.h2so4 as pure water does not have any free ions to conduct electricity. addition of h2so4 results in the dissociation of h+ and oh- ions in the electrolyte ( water).

thus,

h2so4 acts as a catalyst in ionising water into free ions.