Wave optics practice · Medium

Assertion: One of the image in double refraction doesn't obey the principles of refraction.

Reason: Extraordinary image in double refraction doesn't obey the principles of refraction because its velocity changes with direction.

The intensity of gamma radiation from a given source is $I$. On passing through $36\;mm$ of lead, it is reduced to ${I/8}$. The thickness of lead which will reduce the intensity to ${I/2}$ will be

Through which character we can distinguish the light waves from sound waves

In Young’s double-slit experiment, an interference pattern is obtained on a screen by a light of wavelength ${6000\mathop \mathrm{A}\limits^ \circ }$, coming from the coherent sources ${S_1}\;and\;{S_2}$. At certain point $P$ on the screen third dark fringe is formed. Then the path difference ${S_1}P - {S_2}P$ in microns is

The fringe width in Young’s double slit experiment increases when

In Young’s double slit experiment, the intensity of light coming from the first slit is double the intensity from the second slit. The ratio of the maximum intensity to the minimum intensity on the interference fringe pattern observed is

The maximum intensity in the case if $n$ identical incoherent waves, each of intensity $\mathrm{2}\;\mathrm{W}{\mathrm{m}^{ - 2}}$ is $32\;W{\mathrm{m}^{ - 2}}$. The value of n is

Assertion: No interference pattern is detected when two coherent sources are very close to each other. (i.e. separation almost zero).

Reason: The fringe width is inversely proportional to the distance between the two slits.

If the shift of wavelength of light emitted by a star is towards violet, then this shows that star is

The ratio of the intensity at the centre of a bright fringe to the intensity at a point one-quarter of the distance between two fringe from the centre is

When a beam of light is used to determine the position of an object, the maximum accuracy is achieved if the light is

The wavefront of distant source of unknown shape is approximately

A light has amplitude A and angle between analyser and polarizer is $60^\circ$. Light is reflected by analyser has amplitude

What will be the angular width of central maxima in Fraunhoffer diffraction when light of wavelength $6000\mathop \mathrm{A}\limits^ \circ$ is used and slit width is $12 \times {10^{ - 5}}\;cm$

Assertion : If white light is used is YDSE, then central bright fringe will be white.

Reason : Because all the wavelengths produce their zero order maxima at the same position

A Young’s double slit experiment uses a monochromatic source. The shape of the interference fringes formed on a screen is

In Young’s double slit experiment, a third slit is made in between the double slits. Then

In Fraunhofer's single slit diffraction experiment

The two waves having intensities in the ratio $1: 9$ produce interference. The ratio of the maximum to the minimum intensities is equal to

In a Young’s experiment, one of the slits is covered with a transparent sheet of thickness $3.6 \times {10^{ - 3}}\;cm$ due to which position of central fringe shifts to a position originally occupied by ${30^{th}}$ fringe. The refractive index of the sheet, if $\lambda = 6000\mathop \mathrm{A}\limits^ \circ$, is

In Young’s double slit experiment, if the source of light changes from orange to blue, then

The superposition of waves can result in

The resolving limit of healthy eye is about

Figure represents a glass plate placed vertically on a horizontal table with a beam of unpolarised light falling on its surface at the polarizing angle of $57^\circ$ with the normal. The electric vector in the reflected light on screen S will vibrate with respect to the plane of incidence in a

${n^{th}}$ Bright fringe if red light $\left( {{\lambda _1} = 7500\mathop \mathrm{A}\limits^ \circ } \right)$ coincides with ${\left( {n + 1} \right)^{th}}$ bright fringe of green light $\left( {{\lambda _2} = 6000\mathop \mathrm{A}\limits^ \circ } \right)$. The value of $n = ?$

Colours in thin films are due to

A scientist is observing a bacteria through a compound microscope. For better analysis and to improve its resolving power he should. (Select the best option)

Assertion: Transverse wave nature of light is proved by polarisation

Reason: According to Maxwell, light is an electro-magnetic wave but not mechanical wave.

In YDSE if white light is used then.

Which of the following is a dichroic crystal?