I Have a network interface, I have assigned an unicast IP adress to

Can i assign a multicast IP address to it?. (ie Class D IP

My question is -1) When i join an multicast group - does that mean
that i have assigned the
IP address of my interface to multicast IP address?.

In otherwords what will be the source address of the IP packet sent
by a machine which
belongs to a multicast group?.

If i have 2 interfaces - how is this handled - can i specify a
multicast IP address to one
ethernet interface and a unicast ipaddress to another?.

could u please clarify?.