Question

what happens when dilute sulphuric acid is poured on a copper plate

Answer 1

Cu+H2SO4--->Cu2SO4+H2

when H2SO4 poured on copper plate then H2 gas releases.

Answer 2

Copper does not react with dilute sulphuric acid. So, no reaction takes place when dilute sulphuric acid is poured on a copper plate. But when concentrated sulphuric acid is poured over copper plate, effervescence is observed. This happens because of formation of hydrogen gas.
Cu + H2SO4 → CuSO4 + H2