Wave Optics

The intensity at the maximum in a Young’s double slit experiment is I₀. Distance between two slits is d=5λ, where λ is the wavelength of light used in the experiment. What will be the intensity in front of one of the slits on the screen placed at a distance, D = 10 d?

In a diffraction pattern due to a single slit of width a, the first minimum is observed at an angle 30⁰ when light of wavelength 5000 Å is incident on the slit. The first secondary maximum is observed at an angle of

Light of wavelength λ is incident on slit of width d. The resulting diffraction pattern is observed on a screen placed at distance D. The linear width of central maximum is equal to width of the slit, then D=……….

Find the right condition(s) for Fraunhofer diffraction due to a single slit.

The condition for obtaining secondary maxima in the diffraction pattern due to single slit is

To observed diffraction, the size of the obstacle

Wavefront is the locus of all points, where the particles of the medium vibrate with the same

In the Young’s double slit experiment, the intensity of light at a point on the screen (where the path difference is λ) is K, (λ being the wavelength of light used). The intensity at a point where the path difference is λ/4, will be

Colours appear on a thin soap film and soap bubbles due to the phenomenon of

The angle of incidence at which reflected light is totally polarised for refraction from air to glass (refractive index μ) is

A polarised light of intensity I₀ is passed through another polariser whose pass axis makes an angle of 60⁰ with the pass axis of the former. What is the intensity of emergent polarised light from second polariser?

Light of wavelength λ from a point source falls on a small circular obstacle of diameter d. Dark and bright circular rings around a central bright spot are formed on a screen beyond the obstacle. The distance between the screen and obstacle is D. Then, the condition for the formation of rings, is

λ₁ and λ₂ are used to illuminate the slits. β₁ and β₂ are the corresponding fringe widths. The wavelength λ₁ can produce photoelectric effect when incident on a metal. But the wavelength λ₂ cannot produce photoelectric effect. The correct relation between β₁ and β₂ is

When we close one slit in the young’s double slit experiment, then

A parallel beam of fast moving electrons is incident normally on a narrow slit. A flourescent screen is placed at a large distance from the slit. If the speed of the electrons is increased, then which of the following statements is correct?

In a fraunhofer diffraction experiment at a single slit using a light of wavelength 400 nm, the first minimum is formed at an angle of 30. The direction of the first secondary maximum is given by

As a light wave travels from one medium to another which of its following properties will change?

Wave nature of light is verified by

In Young’s experiment, the ratio of maximum to minimum intensities of the fringe system is 4:1. The amplitudes of the coherent sources are in the ratio

In Young’s double silt experiment, 12 fringes are observed to be formed in a certain segment of the screen when light of wavelength 600 nm is used. If the wavelength of light is changed to 400 nm, number of fringes observed in the same segment of the screen is given by

Two beams of light having intensities I and 4I interfere to produce a fringe pattern on a screen. The phase difference between the beams is π/2 at a point A and π at point B. Then the difference between the resultant intensities at A and B is

Newton postulated his corpuscular theory on the basis of

Coherent sources are those sources for which

The dual nature of light is exhibited by

Laser beams are used to measure long distance because

An interference pattern was made by using red light. If the red light is replaced by blue light, the fringes will becomes

Time taken by light to cross a glass slab of thickness 4 mm and refractive index 3 is

What is the time taken by moon light to reach earth?

180⁰ phase difference is obtained when light ray is reflected from

If light emitted from sodium bulb is passed through sodium vapour, then we can get from emergent light

Light propagates rectilinearly because of its

Two coherent sources of different intensities send waves which interfere. The ratio of maximum intensity to minimum intensity is 25:1. The intensities of the sources are in the ratio

Huygen’s principle of secondary wavelets may be used to

The coherence of two light sources means that the light waves emitted have

When one of the slits of Young’s experiment is covered with a transport sheet of thickness 4.8 mm, the central fringe shifts to a position originally occupied by the 30th bright fringe. What should be the thickness of the sheet if the central fringe has to shift to the position occupied by 20th bright fringe?

The frequency of light ray having the wavelength 3000 Å is

In Young’s double silt experiment if the distance between the two slits is made half, then the fringe width will become

In Young’s double slit experiment, the wavelength of the light used is doubled and distance between two slits is made half of initial distance. The resultant fringe width becomes

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 on the interference fringe pattern observed is

Two waves of same amplitude superpose. The resultant intensity is I₁ when they are coherent and I₂ when they are non-coherent. The ratio of I₁ and I₂ will be

A layer of colourless oil spreads on water surface. White light is incident on it and due to interference the oil appears coloured. In order to observe this effect the thickness of oil layer must be of the order of

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

In an interference experiment, third bright fringe is obtained at a point on the screen with a light of 700 nm. What should be the wavelength of the light source in order to obtain 5th bright fringe at the same point?

As a result of interference of two coherent sources of light, energy is

In Young’s double slit experiment, the slit separation is 1 mm and the screen is 1 m from the slit. For a monochromatic light of wavelength 500 nm, the distance of 3rd minima from the central maxima is

A double slit experiment is performed with light of wavelength 500 nm. A thin film of thickness 2 μm and refractive index 1.5 is introduced in the path of the upper beam. The location of the central maximum will

Which of the following phenomena does not show the wave nature of light?

Huygen’s wave theory could not explain

To demonstrate the phenomenon of interference, we require two sources which emit radiations

The maximum number of possible interference maxima for slit-separation equal to twice the wavelength, in young’s double slit experiment is

Which scientist experimentally proved the existence of electromagnetic waves?

Huygen’s wave theory allows us to know

The width of the diffraction band varies

A beam of light of wavelength 600 nm from a distant source falls on a single slit 1 mm wide and the resulting diffraction pattern is observed on a screen 2 m away. The distance between the first dark fringes on either side of the central bright fringe is

If white light is used in Young’s double slit experiment

In the diffraction pattern of a single slit

When the speed of electron beam used in Young’s double slit experiment is increased, then which among the following statements is correct?

Two point white dots are 1 mm apart on a black paper. They are viewed by eye of pupil diameter 3 mm. Approximately, what is the maximum distance at which these dots can be resolved by the eye? [Take wavelength of light =500 nm]

In Young’s double slit experiment with sodium vapour lamp of wavelength 589 nm and the slits 0.589 mm apart, the half angular width of the central maximum is

A single slit Fraunhoffer diffraction pattern is formed with white light. For what wavelength of light the third secondary maximum in the diffraction pattern coincides with the second secondary maximum in the pattern for red light of wavelength 6500 Å?

If separation between screen and source is increased by 2%. What would be the effect on the intensity?

If the ratio of amplitude of two superposed waves is 2:1, then the ratio of maximum intensity and minimum intensity is

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

An unpolarised beam of intensity I₀ falls on a polaroid. The intensity of the emergent light is

In Young’s experiment, the third bright band for light of wavelength 6000 Å coincides with the fourth bright band for another source of light in the same arrangement. Then the wavelength of second source is

A thin film of soap solution (n=1.4) lies on the top of a glass plate (n=1.5). When visible light is incident almost normal to the plate, two adjacent reflection maxima are observed at two wavelengths 420 and 630 nm. The minimum thickness of the soap solution is