So i want to buy an gtx 1050 ti that is pci-e 3.0 but my motherboard (h81m-dg4) is pci-e 2.0 will the gtx 1050 ti work if my motherboard is pci-e 2.0 ?
Yes, PCIE express is backwards and forwards compatible. PCIE 2.0 has plenty of bandwidth for a 1050 ti as well.
And also will it work with this psu nJoy Ayrus 500, 500W Real Power, 80 plus ?
It has plenty of power. However in terms of quality it's not good. Do you already own that? If not I would look for something else. If you want some recommendations post your budget and a store you want to buy from.
Yes, PCIE express is backwards and forwards compatible. PCIE 2.0 has plenty of bandwidth for a 1050 ti as well.
And also will it work with this psu nJoy Ayrus 500, 500W Real Power, 80 plus ?
It has plenty of power. However in terms of quality it's not good. Do you already own that? If not I would look for something else. If you want some recommendations post your budget and a store you want to buy from.