# Wave optics class 12 ncert. NCERT Solutions Class 12 Physics Chapter 10 2018-07-19

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## NCERT Solutions, Wave Optics, Class 12, Physics Class 12 Notes

Which defect he is suffering from? In 1678, the Dutch physicist Christiaan Huygens put forward the wave theory of light — it is this wave model of light that we will discuss in this chapter. The wavelength of light used is 600 nm. The topics covered in Chapter 10 are as follows: Section Number Topic 10. Page No 384: Question 10. According to the law of reflection, the angle of incidence is always equal to the angle of reflection. We are not responsible for any type of mistake in data.

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## NCERT Solutions for Class 12 Physics Chapter 10 Wave Optics in PDF

Interference Two waves whether sound or light of equal frequencies travelling almost in the same direction show interference. What is the justification of this principle? Use the same principle to deduce directly that a point object placed in front of a plane mirror produces a virtual image whose distance from the mirror is equal to the object distance from the mirror. Justify this by suitably dividing the slit to bring out the cancellation. On the one hand, the wavelength of the light waves is too small in comparison to the size of the obstacle. Thus, the bending of the waves takes place at a large angle.

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## NCERT Solutions for Class 12

Then what about the primary school experiment? The energy of the wave travels in a direction perpendicular to the wavefront. Draw the geometrical shape of the wave fronts when. If both light and sound waves can bend around obstacles, how is it that the students are unable to see each other even though they can converse easily. Clearly, all points on such a circle are oscillating in phase because they are at the same distance from the source. Draw the graph of angle of deviation versus angle of incidence using equilateral prism.

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## NCERT Solutions class 12 physics Wave Optics

Estimate the speed with which the star is receding from the Earth. Page No 384: Question 10. It is observed that the first minimum is at a distance of 2. Hence, the speed of violet light is less than the speed of red light in glass. If the source is far off, the wavefront becomes almost a plane.

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## NCERT Class XII Physics: Chapter 10

If not, which alternative picture of light is consistent with experiment? In 1678, the Dutch physicist Christiaan Huygens put forward the wave theory of light — it is this wave model of light that we will discuss in this chapter. What is the spacing between the two slits? Ray optics is based on rectilinear propagation of light, and deals with mirrors, lenses, reflection, refraction, etc. The distance between the central bright fringe and the fourth bright fringe is measured to be 1. As we will see, the wave model could satisfactorily explain the phenomena of reflection and refraction; however, it predicted that on refraction if the wave bends towards the normal then the speed of light would be less in the second medium. Page No 383: Question 10.

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## NCERT Solutions, Wave Optics, Class 12, Physics Class 12 Notes

In case of light waves, sound can travel in a vacuum. Answer: Wavelength of incident monochromatic light, Speed of light in air, Refractive index of water, A The ray will reflect back in the same medium as that of incident ray. If both light and sound waves can bend around obstacles, how is it that the students are unable to see each other even though they can converse easily. Refractive index of water is. Yet the ray optics assumption is so commonly used in understanding location and several other properties of images in optical instruments. From the wave equation, Maxwell could calculate the speed of electromagnetic waves in free space and he found that the theoretical value was very close to the measured value of speed of light. What are the wavelength and frequency of the reflected light? If the flame of the candle and the three pinholes are in a straight line, you can see the candle.

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## NCERT Class XII Physics: Chapter 10

Such a locus of points, which oscillate in phase is called a wavefront ; thus a wavefront is defined as a surface of constant phase. If not, which alternative picture of light is consistent with experiment? On which of these factors, if any, does a The speed of light in vacuum, b The speed of light in a medium say, glass or water , depend? What is the speed of light in glass? What is the longest wavelength of radio waves, which can be sent between the towers without appreciable diffraction effects? If it meets an obstacle of the size of a few metres, it bends around it and reaches points behind the obstacle. What happens there is that when we move any cardboard, the displacement is of the order of a few millimetres, which is much larger than the wavelength of light. How can this defect be corrected? Its optical path becomes t instead of t. Unlike sound waves, two independent sources of light cannot be coherent.

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## Wave Optics class 12 Notes Physics

This is shown in the given figure. The wavelength of light used is 600 nm. Answer: i The shape of a wave front is spherical in the case of a light diverging from a point source. Refractive index of water is 1. What is the spacing between the two slits? It was much later confirmed by experiments where it was shown that the speed of light in water is less than the speed in air confirming the prediction of the wave model; Foucault carried out this experiment in 1850. The distance between the central bright fringe and the fourth bright fringe is measured to be 1. This happens because the transmitted polarization by a polaroid is the component of E parallel to its axis.

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## NCERT Solutions Class 12 Physics Chapter 10

If we have a point source emitting waves uniformly in all directions, then the locus of points which have the same amplitude and vibrate in the same phase are spheres and we have what is known as a spherical wave as shown in Fig. The changing electric and magnetic fields result in the propagation of electromagnetic waves or light waves even in vacuum. Conditions for sustained interference:- i Two sources of light must be coherent. If not, which of the two colours red and violet travels slower in a glass prism? As we will see, the wave model could satisfactorily explain the phenomena of reflection and refraction; however, it predicted that on refraction if the wave bends towards the normal then the speed of light would be less in the second medium. The energy of the wave travels in a direction perpendicular to the wavefront.

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