Question

A low pass filter with cutoff frequency of 250 Hz is NOT suitable for recording ________

• A. Electrocardiogram (ECG)
• B. Electroencephalogram (EEG)
• C. Electromyogram (EMG)
• D. Electrooculogram (EOG)

Hint:

Low pass filters are suitable for signals with frequencies lower than the cutoff frequency. Signals like EMG, which contain higher frequency components, may be adversely affected by such filters.

Answer 1

The Correct Option is C

A low pass filter is designed to allow signals with frequencies below the cutoff frequency (250 Hz in this case) to pass through while attenuating higher-frequency signals.
ECG (Electrocardiogram) and EEG (Electroencephalogram) typically contain low-frequency signals, so a low pass filter with a 250 Hz cutoff is suitable for these.
EOG (Electrooculogram) signals also generally have lower frequencies and would be captured appropriately by the filter. However, the EMG (Electromyogram) records muscle activity, which contains high-frequency components (usually 20 Hz to 500 Hz), and thus, the low pass filter with a cutoff of 250 Hz would not be suitable for EMG recordings, as it would attenuate important signal components.