In a two-slit experiment with monochromatic light, fringes are obtained on a screen placed at some distance from the slits. If the screen is moved by 5 x 10^-2m towards the slits, the change in fringe width is 3 x 10^-5 m. If the separation between the slits is 10-3 m, the wavelength of light used is:
Correct answer: A. 6000 Å
- A. 6000 Å
- B. 5000 Å
- C. 3000 Å
- D. 4500 Å
Explanation
By using the formula for fringe width in a two-slit experiment, the wavelength of light is calculated as 6000 Å. When the screen is moved by 5x10-2m towards the slits, the change in fringe width is 3x10-5m. Given the separation between the slits as 10-3m, the correct answer is 6000 Å.
Last updated
About Optics
Light is studied through reflection, refraction, dispersion, interference, diffraction and polarization, linking ray behavior with its wave nature. Questions may involve mirrors, lenses, optical instruments, refractive index and image formation, while geometrical optics deals with rays and wave optics explains effects such as interference and diffraction.
Practise Optics
665 free Optics 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 7 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
8If the two sound waves produce beats, it is necessary that the two have:
A 16 cm long image of an object is formed by a convex lens on a screen placed normal to its principal axis. On moving the lens towards the screen, without changing the positions of the object and the screen, a 9 cm long image is formed again on the screen. The size of the object is:
A 4 cm high object is located 10 cm from the converging lens, whose focal length is 20 cm. The image so formed will be
A beam of electrons can
A beam of electrons can: