In the reaction 2Ag + 2H2SO4→Ag2SO4 + 2H2O + SO2 sulphuric acid acts as
An oxidizing agent
The sulphur in H2SO4 gets reduced from a +6 oxidation state to +4 in SO2.
Also, we see that Ag0 becomes Ag+1.
This shows that sulphur has gained electrons and got reduced thereby oxidizing others.
So H2SO4 acts as an oxidizing agent.