Wave Optics Tes...

White light may be considered to be a mixture of waves with $$\lambda$$ ranging between $$3900$$ $$\overset{o}{A}$$ and $$7800$$ $$\overset{o}{A}$$. An oil film thickness $$10,000$$ $$\overset{o}{A}$$ is examined normally by the reflected light. If $$\mu =1.4$$, then the film appears bright for.

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A thin air film is formed by putting the convex surface of a piano-convex lens over a plane glass plate. With monochromatic light, this film gives an interference pattern due to light reflected from the top (convex) surface and the bottom (glass plate) surface of the film. 
Statement 1 : When light reflects from the air-glass plate interface, the reflected wave suffers a phase change of $$\pi$$.
Statement 2 : The centre of the interference pattern is dark.

The limit of resolution of an optical instrument is the smallest angle that two points on an object have to subtend at the eye so that they are.

When a red glass is heated in dark room it will seem.

The earth is moving towards a fixed star with a velocity of $$30 km s^{-1}$$ . An observer on the earth observes a shift of $$0.58 A^0$$ in the wavelength of light coming from the star. The actual wavelength of light emitted by the star is then

Choose the Correct answer from alternative given.
The idea of secondary wavelets for the propagation of a wave was first given by:

In the case of the waves from two coherent sources $$S_1$$ and $$S_2$$ , there will be constructive interference at an arbitrary point P, the path difference $$S_1P - S_2P$$ is then

If numerical aperture of a microscope is increased then its

An electron microscope gives higher magnifications than an optical microscope because.

In Young's double slit experiment shows in figure, $$S_1$$ and $$S_2$$ are coherent sources and S is the screen having a hole at a point 1.0 mm away from the central line. White light (400 to 700 nm) is sent through the slits. Which wavelength passing through the hole has the strongest intensity?