Interference in Thin Wedge Films:
Consider the interference pattern produced by the film of varying thickness that is a film which is not plane parallel which is produced by the wedge. It comprises of two non-parallel surfaces inclined at the angle Θ.
Assume the ray of light from the monochromatic source S strikes half silvered mirror and reflected onto an air wedge.
Light from the monochromatic source is partially reflected from mirror onto air wedge. Air wedge is formed by inclining two microscope slides at very small angle Θ as shown in Figure above. If region of reflection at slides is magnified, result is shown in above figure. It can be observe from the figure that some of the light is reflected from lower surface of the top slide and some from top side of the lower slide. Both wave trains R1 and R2 then combine together and gives rise to interference patterns when viewed from above half silvered mirror by the eye or microscope.
Two coherent sources are produce by division of amplitude. This is different from Young's experiment in which sources are produced by division of wave-front.
Phase Change in Reflection:
There is a very important fact concerning reflection of waves from surface of higher refractive index μ. Phase change of Π (or 180o) takes place when light strikes boundary from side of rarer medium.
Therefore, one can say that light reflected by the material of higher refractive index than medium in which rays are traveling goes through a phase change of Π (or 180o). This phase change is equal to path change of λ/2.
The Air Wedge:
In figure given below Θ is an angle of wedge. S is the distance between bright bands. B and B' are two consecutive bright bands.
As Θ is small in triangle ΔACA',
Therefore tan Θ = (λ/2)/s
Or Θ = λ/2s....................Eq.1
Also, the value of tan Θ can be found as
tan Θ = t/a
As value of Θ is very small. Thus
Or Θ = t/a.................Eq.2
On comparing Eq.1 and Eq.2, we get
λ/2s = t/a = Θ
Here Θ is measured in radians
Assume that mth bright fringe is seen above A, one would expect that
2AB = mλ
Generally, band is bright if
2AB = (m - 1/2)λ...............................Eq.4
And for dark band, the condition is
2AB = mλ where m = 0, 1, 2........................Eq.5
If at A', the (m + 1)th bright fringe is seen then it follows that extra path difference is
2A'B' - 2AB = λ
A'B' - AB = λ/2
Tutorsglobe: A way to secure high grade in your curriculum (Online Tutoring)
Expand your confidence, grow study skills and improve your grades.
Since 2009, Tutorsglobe has proactively helped millions of students to get better grades in school, college or university and score well in competitive tests with live, one-on-one online tutoring.
Using an advanced developed tutoring system providing little or no wait time, the students are connected on-demand with a tutor at www.tutorsglobe.com. Students work one-on-one, in real-time with a tutor, communicating and studying using a virtual whiteboard technology. Scientific and mathematical notation, symbols, geometric figures, graphing and freehand drawing can be rendered quickly and easily in the advanced whiteboard.
Free to know our price and packages for online physics tutoring. Chat with us or submit request at [email protected]
The chromosomes are categorized into several types based on shape and position of the centromere.
tutorsglobe.com demerits of mixed economy assignment help-homework help by online mixed economy tutors
tutorsglobe.com functions of nucleus assignment help-homework help by online cell organelles tutors
tutorial all along with the key concepts of Seismic Reflection Method, Seismic Refraction Methods, Seismic Waves , Types of Elastic Wave, Seismic Velocities, Velocities and the Time-Average Equation, Ray-Path Diagrams , Reflection and Refraction
kirchhoffs voltage and current law tutorial all along with the key concepts of electric field and electric potential, kirchhoff's current law, maximum power transfer theorem and miller theorem
www.tutorsglobe.com offers approach of prototyping homework help, assignment help, case study, writing homework help, online tutoring assistance by computer science tutors.
tutorsglobe.com propagation by underground stem assignment help-homework help by online natural methods of vegetative propagation tutors
Simple Harmonic Motion II tutorial all along with the key concepts of Mass Hanging from a Coiled Spring, Period of Oscillation, Simple Pendulum, Energy of Simple Harmonic Motion, Kinetic Energy, Potential Energy
Synthesis and Reactions of Iso-quinolines tutorial all along with the key concepts of Physical and Chemical Properties of Isoquinoline, Synthesis of Isoquinolines, Bischler-Napieralski Synthesis, Picket-Spengler Synthesis and Pomeranz-Fritsch Synthesis
Electron Dynamics tutorial all along with the key concepts of Definition of electron dynamics, Effective mass and Current density
www.tutorsglobe.com offers Functional Budgets homework help, assignment help, case study, writing homework help, online tutoring assistance by accounting tutors.
tutorsglobe.com mendels interpretation and explanation assignment help-homework help by online monohybrid cross tutors
tutorsglobe.com parts of a flowering plant assignment help-homework help by online root-stem and leaf tutors
tutorsglobe.com software coding assignment help-homework help by online software engineering tutors
tutorsglobe.com rain water harvesting assignment help-homework help by online conservation of water tutors
1964139
Questions Asked
3689
Tutors
1460755
Questions Answered
Start Excelling in your courses, Ask an Expert and get answers for your homework and assignments!!