Question

The cut-off frequency of the constant k-low pass filter is?

(a) 1/√LC

(b) 1/(π√LC)

(c) √LC

(d) π√LC

The question was asked in an interview for job.

My question is based upon Constant-K Low Pass Filter in portion Filters and Attenuators of Network Theory

Answer 1

Right choice is (b) 1/(π√LC)

To explain I would say: Z1/4Z2 = 0. Z1 = jωL and Z2 = 1/jωC. On solving the cut-off frequency of the constant k-low pass filter is fc = 1/(π√LC).