Electronics (ECE) - MCQ Practice Questions

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

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?

For a causal discrete-time LTI system with H(z) = 1/(1-0.5z⁻¹), the system is:

A real continuous-time signal has Fourier transform X(f) with magnitude |X(f)| symmetric about f=0. Which property is satisfied?

The pole-zero diagram of a causal system shows poles at z = 0.3 and z = 0.7, with a zero at z = 0. The system is:

The inverse Fourier transform of X(f) = δ(f-f₀) + δ(f+f₀) is:

For a finite impulse response (FIR) filter of length M=5, the maximum linear phase is achieved when:

A system has step response s(t) = 1 - e^(-2t)u(t). Its impulse response h(t) is:

A discrete signal undergoes 16-point FFT computation. The frequency resolution is Δf = 1 kHz. The sampling frequency fs is:

A first-order discrete filter y[n] = 0.8y[n-1] + 0.2x[n] has DC gain (at z=1) of:

For a signal x[n] = cos(πn/4), the fundamental period N is:

A discrete signal x[n] = cos(π n/6) has a period of:

Which of the following is NOT a property of the Laplace transform?

A signal x(t) is band-limited to 1 kHz. Using Nyquist theorem, the minimum sampling rate should be:

For a linear time-invariant system, if input x₁(t) produces y₁(t) and x₂(t) produces y₂(t), then input ax₁(t) + bx₂(t) produces: