This simulation demonstrates the working of a first-order active low-pass filter. The input signal frequency is gradually varied from 10 Hz to 50 kHz. At lower frequencies, the output (blue waveform) follows the input signal (orange waveform) with almost no attenuation, showing that low frequencies pass through the filter. As the frequency increases beyond the filter's cutoff region, the output amplitude starts decreasing, effectively attenuating higher-frequency components while allowing lower