Open a can of roofing cement. This is an asphalt-based glue that will adhere to almost anything. Dip a 2-inch wide brush into the cement and lay a 2-inch line of cement from end to end of the roof, starting at the bottom edge of the building. Be liberal with the cement as you brush it along the roof edge.
In a direct current (DC) circuit, voltage or current is simple to define, but in an alternating current (AC) circuit, the definition is more complicated, and can be done in several ways. Root-mean-square (rms) refersto the most common mathematical method of defining the effective voltage or current of an AC wave. To determine rms value, three mathematical operations are carried out onthe function representing the AC waveform: (1) The square of the waveform function (usually a sine wave) is determined.
V(rms)=sqrt(P(avg)/R) The true RMS voltage is measured using the following method. P(avg) is the average power dissipated in a resistor R when a RMS voltage V(rms) is applied. The power is measured by a thermistor and the scale of the meter is calibrated as a ratio of temperature to resistance.This is true for any waveform and frequencies. Note that most meters you use are not true RMS meters.f it is not you will get false results from them if the load on a circuit is reactive such as a motor or if the wave shape is not a pure sine wave. True RMS instruments can correctly resolve various phase relationships and wave shapes to give you a true RMS reading of voltage and current.