In most cases, when "they" talk about the physical address, they're referring to the MAC. In most networking technologies, they MAC is "burned in" to the NIC (like, in PROM).
A logical address would be like an IP address, an IPX address....usually layer three.
WHile the MAC is "burned in," you may be able to substitute another MAC (the burned in address is still there, it's just not used) , depending on the drivers.
For the sake of Cisco testing, "Physical" refers to the layer two MAC, "Physical" refers to the Layer three address (like an IP or IPX host address).
Good Luck
Scott