The centre of Newton rings is dark due to:
Correct answer: B. Destructive interference.
- A. Polarization
- B. Destructive interference.
- C. Constructive interference.
- D. Reflection.
Explanation
During constructive interference the path difference between the concave lens and the reflective surface i.e. glass slab must be an odd multiple of λ/2, [2n-1×(λ/2)], where n=natural numbers, for destructive interference it must be an even multiple of λ/2, the centre point of newton rings is formed at the point of contact between the lens and the glass. Since the path difference is zero, the condition of destructive interference is satisfied and the centre point is dark.
Last updated
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.
Exams that ask Physics questions like this
Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
A monochromatic light is incident on two slits and an interference pattern is produced on a screen at distance L. Now one slit is covered, and no light comes from it. What is the change in pattern on the screen?
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:
A tuning fork A produces four beats with another tuning fork B. If the frequency of tuning fork B is 320 Hz, then the frequency of tuning fork A is:
A yellow light of wavelength 500 nm emitted by a single source passes through two narrow slits 1 mm apart. How far apart are two adjacent bright fringes when interference is observed on a screen 10 m away?
All of the following are considered as everyday examples of resonance EXCEPT