You would not want to connect Vcc and Gnd together. That would short circuit the power supply.
One pin for phase other pin for neutral and third one is for earth/ground wire. In India the right pin is for phase, left pin is for neutral and pin on top side is for ground wire. This third top side pin is slightly bigger and longer compared to phase and neutral pins.
The ground pin or earth pin is the uppermost pin on your plug. It's purpose is to provide a safety barrier between you and the supply in the event of an overload or in case of an accident.
XLR uses 3 pins, in order 1 = ground, 2 = hot, 3 = cold. You connect those to three pins in the 25 pins, but you need to check the manual of the connected unit which pins to connect them to.
Grounding an electrical or electronics device commonly refers connecting it's power inlet ground pin to the ground connection of the power outlet. The power outlet ground connects to the ground connection provided by the electricity utility company or the building's common ground connection. The grounding essentially provides a zero volt reference. Many systems which have a metal chassis provide specific grounding points with screws/nuts to connect grounding wire. To ground chassis of a computer one need to connect ground wire to the metal case.
On the Mercedes ml320 you should be able to ground the o2 sensor to the body of the car. Just find an unpainted section and stick its ground wire on. If this does not work, try adding an isolation capacitor between the grounding pin and chassis as well. If this still doesn't work, got to the dealer.
Pin 6
You need a hydraulic press to press the pin into the piston and through the connecting rod
Pin you usually refers to pushing some one, as if to pin some one to the ground (push them to the ground).
There isn't any "control" of the ground pin - it is just that - the connection to the common ground. If you mean "How can you make a pin on Arduino go to LOW" (which is the same a zero volts of ground), use the pinMode() function to set a pin to OUTPUT and then issue a digitalWrite() command to that pin setting it to LOW
Pin 1 = ground, Pin 2 = hot/plus, Pin 3 = cold/minus
The LM7805 is a linear voltage regulator that produces a relatively constant output voltage of +5VDC. There is an input pin, which must generally be greater than +7VDC, a ground pin, and an output pin. If the ground pin is connected to a resistor divider network between output and ground, it can be made adjustable for an output voltage greater the +5VDC. Its rating is 1A, but boost circuits can be built to give it more capacity.
I can connect again. Go to logmein123.com and use pin 543636.