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P Pankaj Sanodiya
Let the width of the slit  be divided into n equal parts so that  Now, At this angle, each slit will make the first diffraction minimum. therefore the resultant intensity for all the slits will be zero at the angle of .

P Pankaj Sanodiya
The superposition principle comes from the linear character of the differential equation of wavemotion.that is if  and  are the solution of any wave equation, then linear combination of   and  is also the solution of the wave equation.

P Pankaj Sanodiya
When a low flying aircraft passes overhead, we notice slight shaking in pictures of the TV. This is because aircraft interferes with signals and reflects it. So the shaking we see is the interference of direct signal and reflected signal.

P Pankaj Sanodiya
Given Distance of screen from the slit,  Distance of first minimum  The wavelength of the light  Now, As we know, Hence, the width of the slit is 0.2 mm.

P Pankaj Sanodiya
Given, Distance between two towers = 40km size of aperture =  Now, As we know Fresnel's distance is equal to half of the distance between towers   Also from the formula: Hence this is the required longest wavelength of the radio wave, which can be sent in between the towers without considerable diffraction effect.

P Pankaj Sanodiya
Typical size of the obstacle is much larger than the wavelength of light. Hence the diffraction effect is negligibly small. thus the assumption that light travels in a straight line can be safely used in day to day life.

P Pankaj Sanodiya
The size of obstacle should be comparable to the wavelength for diffraction of waves by obstacles, through a large scale. This comes from This implies  it means the light goes almost unbent and hence student are unable to see each other.

P Pankaj Sanodiya
A bright spot is seen at the centre of the shadow of the obstacle because wave diffracted from the edge of a circular obstacle interfere constructively at the centre of the shadow producing the bright spot.

P Pankaj Sanodiya
When we have a width in the order of  , the intensity of interference fringes in Young's double-slit experiment is modified by the diffraction pattern of each slit.

P Pankaj Sanodiya
As we know, width of the central diffraction band is given by  where d is the width of the slit. So when we double the width of the slit, the size of the central diffraction band reduces to half of its value. But, the light amplitude becomes double, which increase the intensity 4 times.

P Pankaj Sanodiya
Given, Wavelength of light  = 600nm  Angular fringe width  Hence spacing required between the two slits is .

P Pankaj Sanodiya
The sound wave requires a medium for propagation.so, even though both given situation may relate to the same relative motion, they are not identical physically since, the motion of the observer, relative to the medium is different in two situations. Hence, we cannot expect the Doppler formula to be identical in both given cases. When light waves are in a vacuum, there is clearly nothing to...

P Pankaj Sanodiya
The speed of light in any medium depends upon the wavelength of the light and does not depends on the nature of the source, direction of propagation, the motion of the source and/or observer, and intensity of the wave.

P Pankaj Sanodiya
The speed of light in a vacuum is constant and independent of anything according to Einstein's theory of relativity.

P Pankaj Sanodiya
Let an object M is placed in front of a plane mirror AB at a distance r .     A circle is drawn from the centre, such that it just touches the plane mirror at point P. according to the Huygens’ principle, AB is the wavefront of the incident light . If the mirror is absent then a similar wavefront A'B' would form behind M at a distance r.     A'B' can be considered as a virtual reflected ray...

P Pankaj Sanodiya
According to corpuscular theory, when corpuscle of the light goes from rare medium to denser medium, the component of their velocity along the surface of the interface remains the same. So we can write As , That is light should be faster in the dense medium than in rare medium.this is the opposite of what we see experimentally. Huygens wave theory predicts that light is faster in a rare...

P Pankaj Sanodiya
Given, wavelength  Hα line emitted by hydrogen: star is  red-shifted by   let velocity of the star be  Now, as we know, from here Hence speed at which star is receding away is

P Pankaj Sanodiya
Given Aperture  Wavelength of light   Now, Distance for which ray optics is a good approximation also called Fresnel's distance: Hence distance for which ray optics is a good approximation is 40m.