hello
i have one question.
i am using the external supply for the Servo.
Power supply is 5v and 16A.
Servo Motor need 5 volt and 100ma.
so my question is, do i need to limit the current in the Servo motor using
resistor in the series of the Postive wire of the power supply .
Thank you
No. Current is not "pushed in" to the servo or something. A servo will just use 100mA (but I think it will be more then 100mA) of the 16A. It would be a bit weird if that wasn't the case. Your house is connected to power plants that supply 1000's of amps but you're just able to plug in a 3W bulb just fine 
By the way, 16A is a large supply when you don't know basic electronics...
septillion:
By the way, 16A is a large supply when you don't know basic electronics...
i am also using Stepper motor on the same supply and some LED ring and so on.
my total load is 9 A.
in the Worst case if Servo try to suck the more current then what will happen.
i think the servo will burn.
The only way the servo will "suck the more current" is if it was faulty - and if it is faulty it might just burn but clearly, faulty is faulty.
Most servos will draw up to an Amp if commanded to move rapidly or stalled.
The only time they draw more current is under load (or as mentioned above, move rapidly or stalled (ie: under load)..
also as mentioned.. the servo can pull up to 1A (each) under these conditions