Which of the following best describes the "cutoff frequency" of a filter?

A) The frequency at which the output signal is zero

B) The frequency at which the output power is half of the maximum

C) The maximum frequency that can be processed

D) The frequency at which the filter starts to amplify signals

Answer: B) The frequency at which the output power is half of the maximum

Explanation: The cutoff frequency of a filter is defined as the frequency at which the output power drops to half of the maximum power (or -3 dB point). This is a critical parameter in filter design.