Output voltage lag in AC RC low-pass filter

[1talic]

Hi,

Can anyone help simply explain to me why the output waveform in an AC RC low-pass filter circuit lags behind the input signal waveform?

Thanks in advance!

 

[Harald Kapp]

A rather simplistic explanation: the resistor limits the current available to flow into or out of the capacitor therefore it takes some time for a change in input voltage to appear at the output.