Which configuration is known to produce a current or voltage gain?

Which configuration is known to produce a current or voltage gain?

• A. Active filters
• B. Band-pass
• C. Passive filters
• D. Cutoff Frequency

Answer: (A)

Understanding gain in filter circuits comes down to active versus passive elements. An amplifier—an active device such as a transistor or an op-amp—provides power to the signal, so the output can be larger than the input. When a filter uses such an active element, it becomes an active filter and can deliver current or voltage gain while shaping the signal’s frequency content. Passive filters, built only from resistors, capacitors, and inductors without a power source, can filter but cannot amplify; their output is equal to or less than the input. A band-pass describes the range of frequencies the filter passes and can be implemented with either type, but by itself it does not imply gain. The cutoff frequency is simply a point in the frequency response, not a configuration capable of providing gain. Therefore, the configuration that produces current or voltage gain is active filters.

Understanding gain in filter circuits comes down to active versus passive elements. An amplifier—an active device such as a transistor or an op-amp—provides power to the signal, so the output can be larger than the input. When a filter uses such an active element, it becomes an active filter and can deliver current or voltage gain while shaping the signal’s frequency content. Passive filters, built only from resistors, capacitors, and inductors without a power source, can filter but cannot amplify; their output is equal to or less than the input. A band-pass describes the range of frequencies the filter passes and can be implemented with either type, but by itself it does not imply gain. The cutoff frequency is simply a point in the frequency response, not a configuration capable of providing gain. Therefore, the configuration that produces current or voltage gain is active filters.