When a compact disc (CD) is illuminated by small source of white light coloured band are observed. This is due to
- Interference
- Scattering
- Reflection
- Diffraction
The Correct Option is D
Solution and Explanation
Diffraction is the bending or spreading of waves around obstacles or through openings. In the case of a CD, it has a series of closely spaced tracks or grooves on its surface. When white light hits the CD, the grooves act as diffracting elements that cause the light to spread out and interfere with each other. This interference results in the appearance of colored bands or a rainbow-like pattern.
So, the correct answer is (D) diffraction.
Top Questions on wave interference
- For an amplitude modulated wave the minimum amplitude is 3V, while the modulation index is 60%. The maximum amplitude of the modulated wave is
- JEE Main - 2023
- Physics
- wave interference
Two coherent light sources A and B are at a distance 22 from each other ( A = wavelength). The minimum distance from B on the x-axis at which the interference is destructive is- WBJEE JENPAS UG - 2022
- Physics
- wave interference
- The process of superimposing message signal with career wave is known as:
- CUET (UG) - 2022
- Physics
- wave interference
The fringe width for red colour as compare to that for violet colour is approximately
- KCET - 2022
- Physics
- wave interference
- Two coherent sources of light interfere and produce fringe pattern on a screen. For central maximum, the phase difference between the two waves will be
- NEET (UG) - 2020
- Physics
- wave interference
Questions Asked in KCET exam
- The speed of sound in an ideal gas at a given temperature T is v. The rms speed of gas molecules at that temperature is vrms. The ratio of the velocities v and vrms for helium and oxygen gases are X and X' respectively. Then \(\frac{X}{X'}\) is equal to
- KCET - 2023
- Thermodynamics
- If \(p(\frac{1}{q}+\frac{1}{r}),q(\frac{1}{r}+\frac{1}{p}),r(\frac{1}{p}+\frac{1}{q})\) are in A.P., then p, q, r
- KCET - 2023
- Arithmetic Progression
- A stretched wire of a material whose Young's modulus Y = 2 × 1011 Nm-2 has Poisson's ratio of 0.25. Its lateral strain εl = 10-3. The elastic energy density of the wire is
- KCET - 2023
- mechanical properties of solids
- A metallic rod of length 1 m held along east-west direction is allowed to fall down freely. Given horizontal component of earth’s magnetic field BH = 3 × 10-5 T. The emf induced in the rod at an instant t = 2s after it is released is ( Take g = 10 ms-2 )
- KCET - 2023
- Faradays laws of induction
- A 60 W source emits monochromatic light of wavelength 662.5 nm. The number of photons emitted per second is
- KCET - 2023
- Quantum Physics
Concepts Used:
Wave interference
What is Interference?
When two or more waves meet each other then interference happens . Interference is a phenomenon in which 2 or more waves superpose to form a resultant wave of greater, lower or the same amplitude.
There are two types of wave interference:
- Constructive interference
- Destructive interference
The principle of superposition of waves refers that when two or more waves of the same type are incident on the same point, the resultant amplitude at that point is equal to the vector sum of the amplitudes of the individual waves. If the crest of a wave meets the crest of another wave of the same frequency at the same point, sum of individual amplitudes is called as constructive interference.The destructive interference occurs when the maxima of the two waves are at 180 degrees out of phase and a positive displacement of one wave is cancelled exactly by a negative displacement of the other wave.