If the variance σ_x² of d(n) = x(n) - x(n - 1) is one-tenth the variance σ_x² of a stationary zero mean discrete time signal x(n), then the normalized autocorrelation function R_xx(x)/σ_x² at k = 1 is

Which one of the following blocks is not common in both AM and FM receivers?

In Modulation, "carrier" is

Which stage generates RF carrier?

On a smooth surface, the line of sight distance between transmitting antenna (height h_t metres) and receiving antenna (height h_r metres) is about