Electronics (ECE) - MCQ Practice Questions

A system is described by y[n] = 0.8y[n-1] + x[n]. The steady-state gain is:

Which of the following is a property of the Discrete-Time Fourier Transform (DTFT)?

An IIR filter has poles at z = 0.6e^j0.4π and z = 0.6e^-j0.4π. The filter order is:

For a linear-phase FIR filter, the impulse response h[n] must satisfy:

A signal x[n] has Z-transform X(z) = 1 + 2z^-1 + 3z^-2 for |z| > 0. The signal values are:

In a multirate DSP system, downsampling by factor M introduces aliasing if the signal is not:

The convolution of x[n] = {1, 2, 3} and h[n] = {1, 1} yields a sequence of length:

A continuous-time system H(s) = 10/(s+2) is converted using bilinear transformation with T=0.1s. The resulting discrete system pole location is at:

The autocorrelation function R_x[n] of a discrete signal satisfies:

A signal has power spectral density S_x(f) that is nonzero only for |f| ≤ 2 kHz. The minimum sampling frequency is:

For a system with impulse response h[n] = δ[n] + 2δ[n-1], the frequency response magnitude at ω = π is:

A finite-duration signal x[n] has length N=8. Its DFT X[k] has length:

In a Butterworth filter design, increasing the filter order primarily:

The group delay of a filter is defined as:

Which window function has the narrowest main lobe but highest side lobes?

For a real signal x[n], if X[k] is its DFT, then X[N-k] equals:

An analog signal with bandwidth 10 kHz is sampled at 30 kHz. What is the aliased frequency of a 25 kHz component?

A discrete-time signal x[n] = (0.5)^n u[n] is passed through a system with impulse response h[n] = u[n]. What is the output y[n] at n=2?

The Z-transform of x[n] = n·(0.8)^n u[n] is:

A signal x(t) = sin(2πf₀t) is sampled at fs = 5f₀. What is the Nyquist sampling rate required?