If the Nyquist plot cuts the negative real axis at a distance of 0.4, then the gain margin of the system is (a) 0.4 (c) 4 (d) 2.5 [ESE-2001]

(Electronics engineering)- Communication system Answer the a and b question please

The Question is in the attached.

A-The analog signal s(t) = 10 cos (20 pit) cos (200 pi*t) is sampled at the rate of 250 samples per seconds. Determine the following: a- The maximum frequency component present in the analog signal. b-Nyquist rate. B- An analog signal having single frequency as 3 kHz is sampled with 5 kHz signal. Describe its frequency spectrum. What will be the output if the sampled signals are passed through a low-pass filter having cutoff frequency at 2.5 kHz? Q2] A-Discrete samples of an analog signal are uniformly quantized to PCM. If the maximum value of the analog sample is to be represented within 0.05% B- Show that the signal-to-quantization noise ratio in an n-bit binary PCM system, accuracy, find the minimum number of binary digits required per sample. where n is the number of bits uniquely assigned to each of the L quantization levels (L = 2n) is 1.76+6n dB with a sinusoidal analog signal input. 15 Q3] A- A delta modulator system is designed to operate at fi ve times the Nyquist rate for an…