# Tagged Questions

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### Electromagnetic wave in a medium with $\sigma \ne 0$ [closed]

I want to prove that the reflectancy of an Electromagnetic wave in a medium with $\sigma$ $\ne$ 0 is: \begin{align*} R_{\|}=R_{\perp}=\frac{(n-1)^2+k^2}{(n+1)^2+k^2} \end{align*} any advice, please? ...
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### Reflection vs indices of refraction [closed]

A magician during a show makes a glass lens with refractive index 1.47 disappear in a trough of liquid. What is the refractive index of the liquid? Could anyone please demonstrate with a ray diagram?
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### Sharpest camera shoot within a mirror [closed]

In order to take the sharpest camera shoot from the reflected object image in the mirror, the camera should be placed $x\,m$ farther from the reflected image object. How can I determine $x$ ?
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### Evaluating angle of refraction [closed]

Can someone show me how to evaluate the angle of refraction for white light where the angle of incidence is 30 degrees if medium A is air and medium B is water. The answer is 22 degrees. I don't know ...
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### We need to find unit vector along the reflected ray [closed]

A ray of light on a plane mirror comes along a vector $i+j-k$ The normal on incidence point is along $i+j$ we need to find unit vector along the reflected ray. I am not able to solve and draw the ...
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### Bragg's law in photonic crystals

So in photonic crystals when looking at diffraction the refraction of light has to be taken into account. I am told this would lead to the "photonic bragg's law" which is n \lambda = ...
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### Determining distance from object in concave lens [closed]

so I was studying for my Yr11 Physics test tomorrow and I came across a question that I got the wrong answer on, all of my friends are getting the same answer. Question: You wish to project the image ...
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### How many mirrors placed perpendicular to each other shall make a light ray completely reverse its path?

The answer is 3. But according to me 2 shall also work in 2 Dimensions? Does anyone has a theoretical proof?
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### Mirror reflection

Question Create a set-up, as shown in the Figure, consisting of two mirror tiles (A and B) and a bird face, facing to the right . Make sure the two mirrors are perpendicular to the table and ...
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### Doppler effect problem with moving mirror

This was the given question: A light beam of intensity $I$ and frequency $f$, directed along the positive $z$-axis, is reflected perpendicularly from a perfect mirror which itself is moving ...
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### Reflection formula for spherical surface from Fermat's principle (Query)

The snip shows a part of the method shown by my teacher, to describe the reflection formula for spherical surface. However I do not understand how the relation of AB and BI (which I have ...
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### Magnification for a concave mirror

Here is the question as given in my textbook: Find the distance of the object from a concave mirror of focal length 10 cm so that the image size is 4 times the size of the object. The solution ...
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### Confusing mirror problem

A piece of thin spherical shell that has a radius of curvature of 106 cm is silvered on both sides. The concave side of the piece forms a real image 79.5 cm from the mirror. The piece is then turned ...
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### Colors in the secondary rainbow reverse of that in the primary rainbow

Why the colors of Secondary rainbow is reverse of that in the color in the Primary rainbow? What can be the possible reason among the following options Because it is formed by one internal ...
I'm having some trouble figuring out how to get started on this question: If I have a symmetric resonator with two concave mirrors of radii $R$ separated by a certain distance, after how many round ...
A man who is $6$ ft tall is standing in front of a plane mirror that is $2$ ft in length. The mirror is placed lengthwise with its bottom edge $4$ ft above the floor on a wall that is $5$ ft ...