JEE Advanced Important Questions of Ray Optics
FAQs on JEE Advanced Ray Optics Important Questions
1. According to Ray Optics, what is the difference between reflection, refraction and diffraction?
Given how similar these words are and combined with the fact that they are all used in the same chapter, it is not surprising that many students get confused in the terminology. To keep this simple, we’re mentioning below the definitions of all three and the examples you can keep in mind so as to not forget what they mean.
Reflection: Easiest of them all and you probably have studied this even in school days. It is basically the bouncing back of a ray of light when it is incident on a reflective surface like that of a mirror. Otherwise, it would have continued on its linear path. Example: What you see in the mirror is your “reflection” from a plane mirror.
Refraction: This is what students learn after completing their understanding of reflection. It is the change in the direction of light when it encounters a change in medium. A part of the incident ray gets reflected and another part gets refracted. Eg: The formation of a rainbow happens because of refraction.
Diffraction: Diffraction is what takes place when a travelling wave of light encounters either an obstacle or an opening. There are two types of diffraction which are Fresnel Diffraction; Fraunhofer Diffraction. Example: X-Ray diffraction.
2. What are the things learnt in the Ray Optics chapter when preparing for JEE Advanced?
This chapter started by discussing the basic laws of reflection and refraction and further went on to discuss crucial principles and concepts like:
Refractive index and its value for different mediums like water, glass and diamond.
Real and Apparent Depth (by taking examples of objects inside a lake as viewed by a bird and more)
Huygens Principle
Reversibility of light
Total Internal Reflection
Refraction through a prism
Dispersion of light and how it takes place
Dispersion without deviation and deviation without dispersion
Students wanting to score good marks in the advanced in order to secure that position in a College of their choice must take this chapter really seriously and revise all the above-mentioned concepts on a regular basis as these are frequently asked in the JEE advanced.
3. According to the JEE Advanced chapter Ray Optics, why is the Huygens principle so important and how can students make sure they’ve learnt it well enough?
The Huygens principle, also known as the Huygens–Fresnel Principle it is a very important method that helps in the analysis of wave propagation both in near and far-field diffraction. It is crucial not only from the exam point of view but also in the latter part of the students' engineering years. Questions based on this principle are frequently asked in the exam, both in JEE Mains and JEE Advanced. It makes studying this particular topic of extra importance, and hence our subject experts have carefully put together this article that specifically deals with the Huygens principle and everything you need to know about it.
4. What are important points to cover while studying diffraction from the JEE Advanced chapter Ray Optics?
At least one question is almost guaranteed to appear in the exam that tests the students based on their understanding of diffraction. There are quite a few terms that one must be familiar with in order to be able to solve problems based on it. A good enough understanding of Phase Difference, Constructive and Destructive Interference, Compton effect, fringe width and temporal coherence is needed to land the correct answer in the exam. Put simply, Phase difference which is expressed in either degrees or radians is the amount by which a particular wave ‘leads’ or ‘lags’ another wave having the same frequency and starting from the same point. An even value of path difference gives rise to constructive interference while an odd one leads to destructive interference.
5. What does critical angle mean according to the JEE Advanced chapter Ray Optics?
We all know that when a ray of light moves from a denser medium to a rarer medium, it moves away from the normal. There is a special case in which the ray, after refraction, passes by making a 90° angle with the normal. The angle of incidence in such a case is known as the critical angle. Note that this phenomenon only takes place when travelling from a denser medium to a rarer medium and not the other way round. This is because of the simple fact that in the latter case, the ray of light bends towards the normal and hence the angle of refraction is always less than 90° and never equal to it. Students can get access to all the important questions and topics from the website of Vedantu. The student can visit the website and download the study materials in the PDF format for free from the app and website.
