YDSE with White Light – Rankers Physics

Young's Double Slit Experiment: Practice Problem & Solution

Assertion (A): If Young's double slit experiment is performed with white light, the bright fringes produced are white and the dark fringes black. Reason (R): In case of interference, there is no colour splitting.  
Both (A) & (R) are true and the (R) is the correct explanation of the (A)
Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
(A) is true but (R) is false
Both (A) and (R) are false

Short Solution (Best for NEET):

To solve this problem, we apply the core principles of Young's Double Slit Experiment. Understanding the underlying formula is key to arriving at the correct answer below:

When white light is used in YDSE, the central fringe is white. However, other bright fringes are coloured due to dispersion (different wavelengths have different fringe widths). Dark fringes are also not perfectly black. Thus, there is colour splitting. Both A and R are false.

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Similar Practice Questions

Explore conceptually related problems to test your knowledge.

1. Assertion (A): When refractive index of medium is increased resolving power also increases. Reason (R): In medium of higher refractive index wavelength is higher.
2. In the Young's double slit experiment, the ratio of intensities of bright and dark fringes is 9. This means that :- (A) The intensities of individual sources are 5 and 4 units respectively (B) The intensities of individual sources are 4 and 1 units respectively (C) The ratio of their amplitudes is 3 (D) The ratio of their amplitudes is 2
3. Assertion (A): If the phase difference between the light waves emerging from the slits of the Young's experiment is \(\pi\) radian, then central fringe will be dark. Reason (R): Phase difference is equal to \(\frac{2\pi}{\lambda}\) times the effective path difference.  
4. Assertion (A): In Young's double slit experiment, if one of the slits is closed, intensity at the position of central fringe becomes half. Reason (R): Resultant intensity, being sum of intensities from individual slits, becomes half as one slit is closed.  
5. In YDSE setup, light of wavelength 640 nm is used with d = 0.8 m m and D = 1m . If intensity at central maxima is I0 and it's position is y = 0,