Question

What is the phase shift for the foIlowing?
a. A sine wave with the maximum amplitude at time zero
b. A sine wave with maximum amplitude after 1/4 cycle
c. A sine wave with zero amplitude after 3/4 cycle and increasing

Answer 1

Explanation:

Phase of a wave indicates the position of a signal from time t=0.

• One cycle for a sine wave is 360o or 2 radians.

a) A sine wave with maximum amplitude at time t=0. The amplitude of a sine wave is maximum at the peak of the wave.

Case 1: assuming that the wave is starting its cycle at t=0 then there is no phase shift for the wave at time t=0 without considering the amplitude.

Picture 1

Case 2: given the amplitude is maximum therefore the wave form can be assumed to be

Picture 2

Here at t=0 the amplitude is maximum the phase shift from t=0 is ¼ th of the cycle that is 2/4 = 360/4 = -90 degrees.