Does a sim card have to be activated for it to be detected by a phone?

Recently I bought an unlocked iphone off eBay, and I want to try different sim cards with it to see if it is really unlocked. I just want to know if I have to activate the sim card for it to be detected by the phone, and connect to the network.

Fyes

As the phone is unlocked, you can try any SIM card in the phone, you won't have any issue with activation.

1) No. The phone will detect it either way.
2) Yes. If the SIM isn't activated, the network won't let you connect (except perhaps for emergency services).

Yes.