recently i brought coreless motor which 10mm body 7mm circumference, they say it can go upto 50000rpm,can any one tell me what will be the max current it can handle? some say it can handle 2.75A current any practical way to check this? and to generate 2A current @ 3.3V which Mosfet should i use?
With it absent - you should test.
Max current is a non linear function dependent on wire gauge, heat deception and ambient temperature.
Because heat deception is dependent on rotation speed - at some point you may even experience a "paradoxical effect". I.E - running at higher speeds may lower the motors temperature.