khimm19:
i have posted my servo.. can u plss suggest what should i do to control it.. why cant i use the 5v pin of arduino to control it?
When you say "control" presumably you mean "power", because you will control it with a 5V digital output; powering it is a different matter.
According to this page, that MG996R servo needs substantial current. When it's running it draws 500-900mA, but more to the point at stall it requires 2.5A. Stall current is what it draws for a short time each time it starts to move, and of course any time it actually jams.
So you need to provide at least 2.5A just for the servo.
