8 December 2006
"Ohm's Law is the relationship among electric current, resistance, and voltage. The principle is named after the German scientist George Simon Ohm." Webster's Online Dictionary. I will be discussing the uses of Ohm's Law and why it is so important in everyday electrical problems whether it be simple or not. It is everywhere and used by many whether they notice it or not. Ohms law states that current in amperes is equal to voltage divided by resistance. This form of ohms law is most useful for technicians because it is easy to measure voltage with a voltmeter. Connect negative lead of your voltmeter to ground or power source return line and you can measure the voltage on as many things that are accessible to your meter probe that you want. We used this many times when we were calculating current, voltage, or resistance in our labs. It served to be quite a useful shortcut so you don't have to keep using the equipment and wasting valuable time. You can determine the current through a resistor by measuring the voltage on both sides of the resistor, calculating the difference and dividing it by the resistance the resistor. The resistance that is measured is usually written on the side of the resistor or on the box that it comes in. The resistance of a resistor can also be determined by the number, color, and order of stripes on the side of it. That is the most common way of identifying a type of resistor. It is also available from the circuit schematic, or drawing of the circuit for which you are building or testing. Usually one current calculation and several voltage measurements tell you all you need to know about the transistors, diodes, and amplifiers. We have done many different things in class not even noticing that Ohm's Law applies. We calculate things instead of measuring them due to their relationship with what was already measured or what was given. It definitely makes labs a lot...