Concepts Of Physics MCQ Edition [Volume 1]
- Exam
- Concepts Of Physics MCQ Edition [Volume 1]
- Subject
- Physics
- Chapter
- Wave Motion and Waves on a String
Concepts Of Physics MCQ Edition [Volume 1] · Physics · Wave Motion and Waves on a String
Two sine waves propagate in the same direction within a medium....
Two sine waves propagate in the same direction within a medium. Each wave possesses an amplitude of , and the phase difference between them is 120^{}^{{}^{\circ}}. The resultant amplitude is
Options
- A
- B
- C
- D
Correct answer
D.
Step-by-step solution
The resultant amplitude of two waves with amplitudes and and a phase difference is given by
Given , , and \phi = 120^{}^{{}^{\circ}}.
Substituting these values, we get
A_R = \sqrt{A^2 + A^2 + 2(A)(A) \cos 120^{}^{{}^{\circ}}}
Since \cos 120^{}^{{}^{\circ}} = -\dfrac{1}{2},
Given , , and \phi = 120^{}^{{}^{\circ}}.
Substituting these values, we get
A_R = \sqrt{A^2 + A^2 + 2(A)(A) \cos 120^{}^{{}^{\circ}}}
Since \cos 120^{}^{{}^{\circ}} = -\dfrac{1}{2},