what is the sine wave,and frequency at a given r.p.m before the positive and negative rectifying diodes?

Answer 1

waveform:
A waveform is a representation of how alternating current (AC) varies with time. The most familiar AC waveform is the sine wave, which derives its name from the fact that the current or voltage varies with the sine of the elapsed time. Other common AC waveforms are the square wave, the ramp, the sawtooth wave, and the triangular wave.
The sine wave is unique in that it represents energy entirely concentrated at a single frequency. An ideal, unmodulated wireless signal has a sine waveform, with a frequency usually measured in megahertz (MHz) or gigahertz (GHz). Household utility current has a sine waveform with a frequency of 60 Hz in most countries including the United States, although in some countries it is 50 Hz.

The sine wave or sinusoid is a function that occurs often in mathematics, signal processing, alternating-current power engineering, and other fields. Its most basic form is:
y=A*Sin (ωt- φ)
which describes a wavelike function of time (t) with:

peak deviation from center = A (aka amplitude)
angular frequency ω (radians per second)
initial phase (t = 0) = −φ
φ is also referred to as a phase shift. E.g., when the initial phase is negative, the entire waveform is shifted toward future time (i.e. delayed). The amount of delay, in seconds, is φ/ω.

This wave pattern occurs often in nature, including ocean waves, sound waves, and light waves. Also, a rough sinusoidal (inverse cosine) pattern can be seen in plotting average daily temperatures for each day of the year, although the graph may resemble an inverted cosine wave.

Graphing the voltage of an alternating current gives a sine wave pattern. In fact, graphing the voltage of direct current full-wave rectification system gives an absolute value sine wave pattern, where the wave stays on the positive side of the x-axis.
For more:
http://en.wikipedia.org/wiki/sine_wave... Source(s) http://www.kettering.edu/~drussell/demos...

Answer 2

You have asked the same question in several guises. I wonder if you are trying to work out the engine RPM from the alternator frequency, as is the practice with diesel engines. If this is so don’t forget to calculate the engine to generator speed ratio produced by the different pulley sizes.

Answer 3

Another incomplete question ? or am I missing something?