Consider the following assertions:

A: x(t) or x[n] is assumed to be an energy signal  if and only if 0>E>∞  and P=1

B: x(t) or x[n] is assumed to be a power signal only if 0>P> ∞ and E=1

C: x(t) or x[n] is assumed to be a power signal only if  0 < P < ∞ and E= ∞

D:  x(t) or x[n] is assumed to be an energy signal  if and only if 0

Which among them are correct in accordance to energy and power signals?

a. A & B

b. C & D

c. A & C

d. B & D

ANSWER: C & D

Explanation:

According to the property of energy and power signals, a signal is said to be an energy signal only when the value of normalized energy lies within zero and infinity i.e. normalized energy should be greater than zero but less than infinity.

Similarly, Power signals lie within the same range of zero and infinity. This implies that , a signal is known as a power signal only if the value of normalized average power is greater than zero but less than infinity.

Signals which do not satisfy any of these properties are generally known as neither energy signals nor power signals.