Wave Optics Tes...

An astronomical telescope, consists of two thin lenses set $$36 cm$$ a part and has a magnifying power $$8$$. Calculate the focal length of the lenses.

A source of electrons or neutrons can be located at $$S$$. The beam is defined by slits $$S_{1}$$ and $$S_{2}$$. The particles pass through two plates $$P_{1}$$ and $$P_{2}$$ such that the first plate is at zero potential and the second plate can be given any high potential. For using matter waves in a microscope of high resolution which of the following combination must be chosen?

Two thin films of the same material but different thickness are separated by air. Monochromatic light in incident on the first film. When viewed normally from the point $$A$$, the second film appears dark.
From point $$B$$, on normal viewing

$${M}_{1}$$ and $${M}_{2}$$ are plane mirrors and kept parallel to each other. At point O, there will be a maxima for wavelength $$\lambda$$. Light from a monochromatic source $$S$$ of wavelength $$\lambda$$ is not reaching directly on the screen. Then, $$\lambda$$ is:

A parallel beam of white light is incident on a thin film of air of uniform thickness. Wavelengths $$7200\mathring { A } $$ and $$5400\mathring { A } $$ are observed to be missing from the spectrum of reflected light viewed normally. The other wavelength in the visible region missing in the reflected spectrum is

Two identical coherent sources are placed on a diameter of a circle of radius $$R$$ at separation $$x(<<R)$$ symmetrical about the center of the circle. The sources emit identical wavelength $$\lambda$$ each. The number of points on the circle of maximum intensity is $$(x=5\lambda$$):

Two waves of light in air have the same wavelength and are initially in phase. They then travel through plastic layer with thicknesses of $${L}_{1}=3.5mm$$ and $${L}_{2}=5.0mm$$ and indices of refraction $${n}_{1}=1.7$$ and $${n}_{2}=1.25$$ as shown in figure. The rays later arrive at a common point. The longest wavelength of light for which constructive interference occurs at the point is

Two transparent slabs have the same thickness as shown in figure. One is made pf material $$A$$ of refractive index $$1.5$$. The other is made of two materials $$B$$ and $$C$$ with thickness in the ratio $$1:2$$. The refractive index of $$C$$ is $$1.6$$. If a monochromatic parallel beam passing through the slabs has the same number of wavelengths inside both, the refractive index of $$B$$ is

Consider the optical system shown in the figure that follows. The point source of light $$S$$ is having wavelength equal to $$\lambda$$. The light is reaching screen only after reflection. For point $$P$$ to be $$2^{nd}$$ maxima, the value of $$\lambda$$ would be $$(D > > d$$ and $$d > > \lambda)$$ :

Two points sources separated by $$2.0m$$ are radiating in phase with $$\lambda=0.50m$$. A detector moves in a circular path around the two sources in a plane containing them. How many maxima are detected?