Question 3-47F2

Filter characteristics are depicted by how they pass or attenuate signals across a range of frequencies. Curve A shows high amplitude at low frequencies, which then decreases as frequency increases. This behavior is characteristic of a **low-pass filter**, which allows frequencies below a certain cutoff to pass while attenuating higher frequencies. Curve D shows high amplitude at low frequencies, dips significantly in a specific frequency range, and then rises back to high amplitude at even higher frequencies. This "notch" in the response is characteristic of a **band-stop filter** (also known as a notch filter), which attenuates a specific band of frequencies while passing frequencies above and below that band. Therefore, the statement "A is a low pass curve and D is a band stop curve" is true. For the other curves, B represents a band-pass filter, and C represents a high-pass filter. The incorrect options misidentify these characteristics.