Eye Strain. When you stare at screens all day, your eyes can get tired. Take a break with the 20/20/20 rule. Look at an object at least 20 feet away for 20 seconds every 20 minutes, says Ivan Schwab, MD, a spokesman for the American Academy of Ophthalmology.
Once you have the dial on your volt meter set to measure voltage, simply touch the black lead to the negative (-) terminal on your battery and the red lead to the positive ( ) terminal on your battery.
Re: Measure the length of a wire, electrically. You could measure the resistance, but you would need access to both ends of the wire. If you have a good building ground and regulated power supply, you could measure the voltage drop from one end to the other.