Electronics (ECE) - MCQ Practice Questions

The energy of signal x(t) = e^(-2t)u(t) is:

Which property does NOT apply to the Laplace transform?

A signal x[n] is time-reversed to get x[-n]. This operation is:

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

A signal is called energy signal if:

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

For a real signal x(t), its Fourier transform X(f) satisfies:

An LTI system has impulse response h(t) = e^(-3t)u(t). Is this system stable?

The output of a system is y[n] = 0.5y[n-1] + x[n]. What is the transfer function H(z)?

A sinusoidal signal x(t) = 5sin(2πf₀t + π/4) is sampled at fs = 10f₀. What is the Nyquist frequency?

Which window function provides the narrowest main lobe but highest side lobes in frequency domain?

For a sequence x[n] = {1, 2, 1, -1}, what is the circular convolution with itself using 4-point DFT?

A signal has autocorrelation R_x(τ) = Ae^(-2|τ|). What is its bandwidth (3dB) approximately?

A filter has poles at z = 0.7 and z = 0.9. What can we infer about its stability and response?

An analog filter has magnitude response |H(jω)| = 1/√(1+(ω/ωc)⁴). What is the order of the filter?

A real discrete signal x[n] has DTFT X(e^jω). What is the relationship between X(e^jω) and X(e^-jω)?

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

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:

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