Two sound waves having the same amplitudes are moving in the same direction are out of phase. The amplitude of the resultant wave is:
Correct answer: A. Zero amplitude
- A. Zero amplitude
- B. The sum of the amplitudes of the two waves
- C. Difference of the amplitudes of the two waves
- D. Double the amplitude of either wave
Explanation
The correct answer is A) Zero amplitude. When two sound waves with identical amplitudes are completely out of phase, they interfere destructively, effectively cancelling each other and resulting in a net amplitude of zero. Option B is incorrect because the sum of amplitudes occurs during constructive interference when waves are in phase. Option C is incorrect because the difference in amplitudes applies when the waves have different amplitudes or are not fully out of phase. Option D is incorrect because doubling of amplitude happens during constructive interference of in-phase waves.
This question appeared on the UHS MDCAT 2010 paper, which you can sit online with every answer explained.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Superposition and Interference
Superposition states that overlapping waves produce a resultant displacement equal to the algebraic sum of their individual displacements. Interference covers constructive and destructive interference, phase difference, path difference, coherent sources, and conditions for maxima and minima. It differs from diffraction, which involves spreading around openings or obstacles.
Practise Waves
1,281 free Waves MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Physics questions like this
Physics is on 16 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Superposition and Interference questions
In Michelson's interferometer 792 bright fringes pass across the field of view when its movable mirror is displaced through 0.233 mm using the equation l = m λ / 2 the wavelength of light used is:
In Young's Double Slit Experiment, if the distance between slits and screen is doubled, then fringe spacing becomes:
Two waves of slightly different frequencies and travelling in the same direction lead to:
A source 'Y' of unknown frequency produces 4 beats with a source of 240 Hz and 8 beats with a sound of 252 Hz. Frequency of the source 'Y' is:
The path difference 'BD' for destructive interference is:
For interference of light waves to take place, the required condition is: