With regards to ELTs on Airbus aircraft. There would have been likely three ELTs on the aircraft. One is fixed, its located in the rear ceiling area of the cabin with an external antenna, its the small antenna in front of the fin. Its controls are located in the overhead panel in the flightdeck. As the aircraft is likely to of broke up the chances are the ELT and antenna still being in serviceable state are very small.
There are also two portable ELTs located in the cabin but these would have to be activated by anyone that could have got to them.
Some information about the ELTs that may have been to this MSN are found here:
ELTA : Elt, power supply, satellite transmission, physico-chemical analysis
As for the ELBs on the DFDR and CVR these activate on contact with water. If you want some specs here's a website for the manufacurer of one type of ELB its:
Dukane Seacom Aviation Products