Discrete-Time Signals and Systems Worksheet

In a sampled system with a switch rotating at 500 rpm and closing for 10 ms each time, what type of discrete-time signal is produced if sampling is ideal?

• Continuous-time signal

• Discrete-time signal

• Random noise

• Sinusoidal signals

Which of the following is a discrete-time function defined only at integers?

• x(t)

• x[n]

• X(f)

• δ(t)

What is the result of graphing y[n] = x₁[n] + 4x₂[n], where x₁ and x₂ are discrete-time functions?

• Scaled sum of x₁ and x₂

• Product of x₁ and x₂

• Only x₁ scaled by 4

• Only x₂ scaled by 4

What is the only nonzero value of the discrete-time function defined by x[n] = δ[n − 15]?

• At n = 0

• At n = 15

• At n = −15

• For all n

For a discrete-time signal defined as zero for all n outside the range, how is its range described?

• Infinite

• Finite nonzero interval

• Periodic over integers

• Undefined

A summation of unit impulses starting at n = a and continuing through n = b is:

• A single impulse at n = a

• Multiple impulses at integers between a and b

• Continuous function

The amplitude comparison of two signals helps determine:

• Relative scaling factor

• Phase shift

• Time delay

• Frequency difference

The width comparison in signal decimation indicates:

• Time scaling

• Amplitude scaling

• Frequency response

• Phase distortion

What does the accumulation of a discrete-time function represent?

• Sum of function values up to n

• Derivative of the function

• Signal inversion

• Periodicity

The sum of the squares of signal values over one period relates to:

• Average power

• Signal duration

• Maximum amplitude

• Signal phase