When a beam of light travleing in a rare medium is reflected from a denser medium it:
Correct answer: B. Undergoes a phase change of 180°
- A. Suffers no phase change
- B. Undergoes a phase change of 180°
- C. Undergoes a phase change of 270°
- D. Undergoes a phase change of 90°
Explanation
When light waves hit the boundary of a denser medium, some of it is transmitted/refracted and some is reflected. When a wave undergoes a reflection at a denser medium then its crest is reflected as a trough and vice versa. So its phase changes at 180 degrees or pi. Hence the correct option is B. The image given below is the summary of this concept:
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: