Question

Which of the following statements are correct ?
1. All signals having infinite energy are power signals.
2. A finite amplitude periodic signal is a power signal.
3. A signal cannot be both energy and power signal.
4. Time scaling has no effect on signal energy.

• A. 2,3 and 4 only
• B. 2 and 3 only
• C. 1, 2 and 3
• D. 1 and 4 only

Answer 1

The correct option is B 2 and 3 only

There are signal having infinite energy have infinite power as well
e.g., x (t) = r(t)
$E_x=\infty$
$P_x=\infty$
Hence neither an energy signal nor power signal
Time scaling does not affect power of signal, while energy of the signal is affected,
$E\left(at\right)\to \frac{E\left(t\right)}{a}$