i have found a computer UPS battery which is giving 9 volt but only 0.5 amps.is that can be used for anyother purpose?

 

Sure as long as that purpose can use 9V @ .5A . Many devices use a 9V battery. Whether your UPS battery will supply enough energy depends on its residual capacity vs the needs of a projected usage. Your question is pretty nebulous and therefore needs more specific information to enable providing real useful answers. The battery you mention likely has 2 shorted cells so depending on the condition of the remaining ones you might get some use from it.

 

Presumably this is a 12V SLA?? If it has been charged with a working charger, and only manages 9V, I'd pronounce it dead..... How long can it deliver 0.5A for at that voltage??