Analog and Digital Filters Questions and Answers for Viva

Answer-1: A filter is a circuit capable of passing (or amplifying) certain frequencies while attenuating other frequencies. Thus, a filter can extract important frequencies from signals that also contain undesirable or irrelevant frequencies.

Answer-2: Analog filters process continuous-time signals, whereas digital filters process discrete-time signals.

Answer-3: Resistors, capacitors, and inductors are the typical components used in analog filters.

Answer-4: Analog filters typically offer smoother response and lower latency.

Answer-5: Digital filters provide greater flexibility and precision in signal processing.

Answer-6: The four primary types of filters include the low-pass filter, the high-pass filter, the band-pass filter, and the notch filter (or the band-reject or band-stop filter).

Answer-7: The cutoff frequency determines the point at which the filter begins to attenuate frequencies.

Answer-8: The order of a filter is determined by the number of reactive components (capacitors and inductors) in an analog filter or the number of coefficients in a digital filter.

Answer-9: Filter response describes how a filter behaves across different frequencies, typically represented by a frequency response curve.

Answer-10: A Butterworth filter is a type of analog or digital filter with a maximally flat frequency response in the passband.

Answer-11: A Chebyshev filter is designed to have a steeper roll-off than a Butterworth filter, sacrificing passband flatness for improved stopband attenuation.

Answer-12: FIR filters have a finite duration impulse response, meaning that the output response decays to zero in a finite amount of time.

Answer-13: FIR filters are implemented using convolution, often through techniques like the windowing method or the frequency sampling method.

Answer-14: Linear-phase filters have a constant group delay across all frequencies, while minimum-phase filters have the minimum possible phase shift for a given magnitude response.

Answer-15: The Nyquist frequency represents half the sampling rate and determines the maximum frequency that can be accurately represented in a digital signal.

Answer-16: Linear-phase filters have a constant group delay across all frequencies, while minimum-phase filters have the minimum possible phase shift for a given magnitude response.

Answer-17: The Gibbs phenomenon causes overshoot and ripple in the frequency domain when sharp transitions occur in the time domain, which can affect the performance of digital filters.

Answer-18: The transition band is the frequency range between the passband and stopband where the filter's response transitions from allowing to attenuating frequencies, and its width determines the filter's selectivity.

Answer-19: Quantization error refers to the error introduced by representing continuous values with discrete values, which can occur during the analog-to-digital conversion process in digital filters.

Answer-20: There are many practical applications for filters. Radio communications, DC power supplies, Audio electronics, Analog-to-digital conversion.