Question

Why does not silver evolve hydrogen on reacting with dilute H2SO4

Answer 1

Silver is less reactive than hydrogen and so placed below hydrogen in the reactivity series. Metals which are less reactive than hydrogen cannot displace hydrogen from acids. This is why silver does not displace H2 when it reacts with dil H2SO4. So, when silver metal is added to dilute H2SO4, no reaction takes place. 
it is because, silver lies below hydrogen in electrochemical series. so it cannot reduce the hydrogen and replace it.

Ag + H2SO4 → no reaction