i bought an arduino uno and i need to drive it using an external battery not with the usb, however on my tutorial sheet it says that i need to put the jumper onto the external battery for the arduino to recognize it. And i cant seem to find it. what can I do? did i order the wrong board?
Thanks
There is a coaxial power connector on the corner of your Arduino board. You need to get a connector for that jack, center pin is + outside is -. You need to feed it with a supply of greater than 7V (9 is better) and less than 20V. the higher the voltage the hotter the 5V regulator on the Arduino board will run.
Thanks for your reply 
But i dont know which is the coaxial connecter 
I was just going to connect it with the battery and see if it moves, because i cant see any jumpers 
because i cant see any jumpers
That is a very old tutorial sheet. There hasn't been a power jumper on an arduino for about 4 years. It is switched automatically on the modern arduinos.
You can connect to the Vin/Gnd pins on the power header. Be sure not to get them backwards as Vin is After the reverse polarity protection diode.
See D1 on the top right of the schematic.
Thank You so much guys, I am a beginner in arduino and I still dont know what is happening
Thanksss 