Answer:
Resulting amplitude, A = 0 cm
Explanation:
The phenomenon of interference occurs when two travel and meet at the same point. There are two conditions for interference. The first one is constructive and the other one is destructive.
In this case, two waves have same amplitude but they are not in same phase such that they meet at point X and destructive interference occurs.
Let A is the amplitude of the resulting wave such that,
A = 0
So, the amplitude of the resulting wave is 0 cm. Hence, the correct option is (A).
