A beam of light consisting of red, green and blue colour is incident on a right-angled prism. The refractive indices of the material of the prism for the above red, green and blue wavelength are 1.39, 1.44 and 1.47 respectively. The prism will:
Correct answer: A. Separate part of red colour from the green and the blue colour
- A. Separate part of red colour from the green and the blue colour
- B. Separate part of the blue colour from the red and green colour
- C. Separate all the colours from one another
- D. Not separate even partially any colour from the other two colours
Explanation
A prism disperses light into its constituent colors due to varying refractive indices for each wavelength. In this scenario, the red light has the lowest refractive index (1.39), followed by green (1.44), and blue (1.47). Because red light will deviate the least, it is likely to separate partially from the green and blue light, which deviate more. The blue light, having the highest refractive index, will deviate the most. Thus, the correct answer is that the prism will 'Separate part of red colour from the green and the blue colour.' The statement in Option D is incorrect as some separation is inevitable due to the nature of dispersion, and Option C is incorrect because complete separation of all colors does not occur in a right-angled prism. Option B is less likely because it suggests a scenario of partial separation for blue, which is less feasible given the context.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
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.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Physics questions like this
Physics is on 11 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Optics questions
An object is placed in front of a convex mirror at a distance of 50cm. A plane mirror is introduced covering the lower half of the convex mirror. If the distance between the object and the plane mirror is 30cm, it is found that the images formed by the two mirrors are along the same line. The radius of curvature of the mirror will be:
A thin rod of length f/3 lies along the axis of a concave mirror of focal length f. One end of its magnified image touches an end of the rod. The length of the image is:
A candle flame of height 3cm is placed at a distance of 3m from a wall. How far from the wall must a concave mirror be placed so that it may form an image of the flame 9cm high on the wall:
The figure given below shows a beam of light converging at point P. When a covex lens of focal length 16cm is introduced in the path of the beam at a place O shown by a dotted line such that OP becomes the axis of the lens, the beam converges at a distance x from the lens. The value x will be equal to:
An air bubble in a glass sphere having a 4cm diameter appears 1cm from the surface nearest to the eye when looked along the diameter. If µg = 1.5, the distance of the bubble from the refracting surface is:
Two point light sources are 24cm apart. At what distance from one source must a convex lens of focal length 9cm be kept in between them so that the images of both the sources are formed at the same place?