Concert Sound and Lighting Systems, 3rd Edition

APPENDIX B

CIRCUIT LAWS AND CABLE WIRING

OHM'S LAW  

The relation between voltage, current, and resistance in a circuit is defined by Ohm's law, which is simply stated by the following formula:

E = IR

where E is in volts, I is in amperes, and R is in ohms. This can also be stated as follows:

I = E/R

or

R = E/I

RESISTORS IN SERIES  

To find the total resistance in a series circuit, simply add together all resistors. In other words, a 10-ohm, a 150-ohm, and a 1,000-ohm resistor connected in series would equal a single 1,160-ohm resistor. The formula ...