Total Internal Reflection
Total Internal Reflection
When a ray of light travels from denser(higher refractive index) to the rarer (low refractive index) medium, it bends away from the normal . This means that angle of refraction is greater than angle of incidence
. With increase in the angle of incidence, the angle of refraction also increases.The figure below shows the incident ray in red colour, the refracted ray with blue colour and the green colour ray shows the part of ray which is reflected.
At a particular value of called as critical angle the angle of refraction becomes
.At this angle refracted ray then comes out parallel to the surface seprating the two media The figure below shows the incident ray in red colour, the refracted ray with blue colour and the green colour ray shows the part of ray which is reflected. We see that the blue ray grazes the surface seprating the two media.
The relation between the critical angle and the refractive index is
As we increase the angle above the critical angle it results in reflecting back of the ray into the same medium. This reflection obeys the law of reflection therefore angle of reflection of ray is equal to the angle of incidence
above the critical angle. The figure below shows the incident ray in red colour, As the angle of incidence is more than the critical angle there is no refracted ray hence there is no blue coloured ray and the green colour ray shows the reflected ray, which follows the laws of reflection..
Thus the total internal reflection of light takes place when a ray of light travels in a denser medium and is incident on the boundary with rarer medium at an angle greater that the critical angle. It is known as total reflection because when a ray falls obliquely on the interface of the two transparent medium, a part of it is reflected and a part of it is refracted. When the angle of incidence is greater than critical angle, the whole of the light ray is reflected. Hence it is called total internal reflection.
For and
, from Snell's law
Substituting the values of i and r, we get
In the case of total internal reflection the higher the refractive index of the ______________ medium, the smaller is the critical angle for the pair. | |||
| Right Option : A | |||
| View Explanation | |||
The angle at which the light ray travelling from a denser to a rarer medium gets totally reflected back into the same medium is | |||
| Right Option : C | |||
| View Explanation | |||
Which of the following are correct ? (a) When a ray of light travels from rarer to the denser medium, it bends away from the normal .With increase in the angle of incidence, the angle of refraction also increases. (b) When the angle of incidence is greater than critical angle, the whole of the light ray is reflected. Hence it is called total internal reflection . (c) The critical angle is different for different pairs of media. | |||
| Right Option : B | |||
| View Explanation | |||
Students / Parents Reviews [20]
Abhyas is good institution and a innovative institute also. It is a good platform of beginners.Due to Abhyas,he has got knoweledge about reasoning and confidence.My son has improved his vocabulary because of Abhyas.Teacher have very friendly atmosphere also.
Manish Kumar
10thI have spent a wonderful time in Abhyas academy. It has made my reasoning more apt, English more stronger and Maths an interesting subject for me. It has given me a habbit of self studying
Yatharthi Sharma
10thMy experience with Abhyas is very good. I have learnt many things here like vedic maths and reasoning also. Teachers here first take our doubts and then there are assignments to verify our weak points.
Shivam Rana
7thUsually we see institutes offering objective based learning which usually causes a lag behind in subjective examinations which is the pattern followed by schools. I think it is really a work of planning to make us students grab the advantages of modes of examination, Objective Subjective and Onli...
Anika Saxena
8thAbhyas Methodology is very good. It is based on according to student and each child manages accordingly to its properly. Methodology has improved the abilities of students to shine them in future.
Manish Kumar
10thWe started with lot of hope that Abhyas will help in better understnding of complex topics of highers classes. we are not disappointed with the progress our child has made after attending Abhyas. Though need to mention that we expected a lot more. On a scale of 1-10, we would give may be 7.
Manya
8thAbhyas institute is one of the best coaching institute in the vicinity of Ambala Cantt area. The teachers of the institute are well experienced and very helpful in solving the problems of the students.The good thing of the institute is that it is providing extra classes for the students who are w...
Aman Kumar Shrivastava
10thAbhyas academy is great place to learn. I have learnt a lot here they have finished my fear of not answering.It has created a habit of self studying in me.The teachers here are very supportive and helpful. Earlier my maths and science was good but now it has been much better than before.
Barkha Arora
10thAbhyas institute is one of the best coaching institute in the vicinity of Ambala cantt.The institute provides good and quality education to the students.The teachers are well experienced and are very helpful in solving the problems. The major advantages of the institute is extra classes for weak...
Shreya Shrivastava
8thIt has a great methodology. Students here can get analysis to their test quickly.We can learn easily through PPTs and the testing methods are good. We know that where we have to practice
Barkha Arora
10thIn terms of methodology I want to say that institute provides expert guidence and results oriented monitering supplements by requsite study material along with regular tests which help the students to improve their education skills.The techniques of providing education helps the students to asses...
Aman Kumar Shrivastava
10thMy experience with Abhyas Academy has been very good. When I was not in Abhyas whenever teacher ask questions I could not speak it confidently but when I came in Abhyas, my speaking skills developed and now I am the first one to give the answer of teachers question.
Upmanyu Sharma
7thWhen I have not joined Abhyas Academy, my skills of solving maths problems were not clear. But, after joining it, my skills have been developed and my concepts of science and SST are very well. I also came to know about other subjects such as vedic maths and reasoning.
Sharandeep Singh
7thOne of the best institutes to develope a child interest in studies.Provides SST and English knowledge also unlike other institutes. Teachers are co operative and friendly online tests andPPT develope practical knowledge also.
Aman Kumar Shrivastava
10thAbhyas is an institute of high repute. Yogansh has taken admission last year. It creates abilities in child to prepare for competitive exams. Students are motivated by living prizes on basis of performance in Abhyas exams. He is satisfied with institute.
Yogansh Nyasi
7thIt was good as the experience because as we had come here we had been improved in a such envirnment created here.Extra is taught which is beneficial for future.
Eshan Arora
8thBeing a parent, I saw my daughter improvement in her studies by seeing a good result in all day to day compititive exam TMO, NSO, IEO etc and as well as studies. I have got a fruitful result from my daughter.
Prisha Gupta
8thMy experience with Abhyas academy is very nice or it can be said wonderful. I have been studying here from seven class. I have been completing my journey of three years. I am tinking that I should join Abhyas Academy in tenth class as I am seeing much improvement in Maths and English
Hridey Preet
9thMy experience was very good with Abhyas academy. I am studying here from 6th class and I am satisfied by its results in my life. I improved a lot here ahead of school syllabus.
Ayan Ghosh
8thThe experience was nice. I studied here for three years and saw a tremendous change in myself. I started liking subjects like English and SST which earlier I ran from. Extra knowledge gave me confidence to overcome competitive exams. One of the best institutes for secondary education.
