Which among the following are also known as "Delay Equalizers" ?

Which among the following are also known as “Delay Equalizers” ?

a. Band Elimination Filter
b. Band-pass Filter
c. All-pass Filter
d. High pass filter

Correct Answer : c. All-pass Filter

Explanation :

All-pass filters allows to pass all the frequency components of input signal without any attenuation by anticipating phase shifts for different frequencies. When signals undergo transmission by telephone wires, there is a definite change in phase. Thus, all pass filters are the means for compensating these phase changes,because of which they are generally termed as “Phase-Correctors” or “Delay Equalizers”. Output of Delay Equalizers can be generated by using Super-position theorem.