18-10-2016, 11:00 AM
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Q1. What is an ideal low pass filter ?
Ans: An ideal low pass filter is a network which passes all the frequency up to cut-off frequency fc, and blocks all frequencies above fc.
Q2. What is difference between an ideal and a practical low pass filter ?
Ans: The transition region present in practical filters doesn’t exist in an ideal filter. An ideal low-pass filter can be realized mathematically by multiplying a signal by the rectangular function in the frequency domain or, equivalently, Convolution with a sinc function in the time domain.
Q3. What does the term “pass” mean in any low-or-high pass filters ?
Ans: Pass: to cause or permit to go past or through a barrier.
Q4. What are passive filters ?
Ans: Passive filters are implemented using only passive components such as resistors, capacitors and inductors. These filters do not produce any amplification of the input signal.
Q5. What is a low-pass filter ?
Ans: a low pass filter is a filter that passes low frequency signal but attenuates signal with frequencies higher than the cut-off frequency.
Q6. What are active filters ?
Ans: Active filters are the circuits that use an operational-amplifier as the active device in combination with some resistors and capacitors to provide an LRC-like filters performance at low frequencies.
Q7. What are elements of passive filter?
Ans. The elements are inductor, capacitor and resistor.
Q8 What are advantages of active filter over passive filter?
Ans. The advantages are:-
1. gain and frequency adjustment flexibility.
2. No loading problem 3. Cost is low.
Q9. What are the application of filter?
Ans. The Filter is used in voice frequency telegraphy,multichannel communication, TV broadcasting and telephony.