Answer Posted / john h

Unless you are refering to Instant AC values. AC is wave
form and its values change all the time in voltage as in
current and power. Most AC values are given in root means
Square or RMS. this RMS value is represented the heating
effect this heating effect is the same in AC as DC. so a
50A AC has the same heating effect as a 50A DC.

For isntance regular unshaped AC (household wall outlet) is
a sine wave with 2 peaks a + source Pk and a - sourced Peak
this represents the direction of current flow as the + and -
switch as the waveform aproaches its 0 point.

so a if you are drawing 5A AC the values changes based on
its 360 degree rotation 0,180,360 are all 0 points 90 being
your + peak value and 270 your -. 5A AC will actually peak
at 7.012 Amps + and - on a normal sinewave form.

to get your pk values take your normally stated A or V or
even P and divide by half the square root of 2 which is
normally seen as the .707 value. so 5A /.707 gives you the
7.012A. As i mentioned earlier a non peak AC current is
stated in its heating effect on a load.

If you happen to be dealing with something that has a
strict threshhold make sure it can sustain a peak value if
it is AC a 120V socket peaks at 169.731V where a DC value
does not change unless there is a change to the supply or
circuit. a capacitor 120V will accept any AC or DC voltage
to 120V but if you are using standard 120V AC 120V peaks at
169.7V surpassing the breakdown voltage of the capacitor.
it works this way with power and current as well.

An 8 pole, 50 Hz, 3-phase IM is loaded to a poing where pull out torque will occur. The rotor resistance per phase is 0.3 ohm and motor stalls at 650 rpm. The slip when motor stalls is A 1 B 0 C 13.33% D 10.33%

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