(a) Design a low-pass OP AMP circuit to pass only the fundamental and the next nonzero harmonic of a 20π ms square wave. The gain of the OP AMP should be +5.
(b) Find the first four nonzero terms in the Fourier series of the output of your filter.
(c) Validate your design using Multisim. The OP AMP's VCC = ± 15 V.