What type of ac voltage and current reading is measured by a digital multimeter? Is it RMS, peak or peak-to-peak values?

 

Usual multimeters measure RMS values. Maybe some special mutlimeters measure peak and peak-peak.

 

It will be either RMS or average, as described in the instrument's manual.

 

And on AC measurements most meters assumes a sine wave, if not then the measurement will have a error factor. Some more expensive DVM have true rms circuitry to handle non-sinewave waveforms.

Lefty