Home
Class 12
PHYSICS
A plane wavefront is divided into a numb...

A plane wavefront is divided into a number of half period zones as per Fresnel theory. The resultant amplitude at a point due to secondary waves spreading from a zone is

A

directly porportional to the square root of the area of the zone

B

inversely proportional to the square of the distance of the point from the zone

C

inversely proportional to the distance of the point from the zone

D

independence of obliquity

Text Solution

Verified by Experts

The correct Answer is:
C
Promotional Banner

Topper's Solved these Questions

  • WAVES OPTICS

    AAKASH SERIES|Exercise EXERCISE -IA (POLARASATION)|29 Videos

  • WAVES OPTICS

    AAKASH SERIES|Exercise EXERCISE -IA (SATEMENT TYPE QUESTIONS)|12 Videos

  • WAVES OPTICS

    AAKASH SERIES|Exercise EXERCISE -IA|54 Videos

  • WAVES

    AAKASH SERIES|Exercise EXERCISE-III (Doppler effect :)|15 Videos

Similar Questions

Explore conceptually related problems

A cylindrical wavefront is divided into number of Fresnel.s half period elements. With the increase of the order of the element, the area of the element

Huygen was the first scientist who proposed the idea of wave theory of light. He said that the light propagates in form of wavefronts. A wavefront is an imaginary surface at every point of which waves are in the same phase. For example the wavefronts for a point source of light is collectionof concentric spheres which have centre at the origin. w_(1) is a wavefront. w_(2) is another wavefront. The redius of the wavefront at time 't' is 'ct' in this case where 'c' is the speed of light. The direction of propagation of light is perpendicular to the surface of the wavefront. The wavefronts are plane wavefronts in case of a parallel beam of light. Huygen also said that every point of the wavefront acts as the source of secondary wavelets. The tangent drawn to all secondary wavelets at a time is the new wavefront at that time. The wavelets are to be consid-ered only in the forward direction ( i.e. the direction of propagation of light) and not in the reverse direction. If a wavefront w_(1) at time t is given, then to draw the wavefront at time t+Deltat0 take some points on the wavefront w_(1) and draw spheres of radius 'cDeltat'. They are called secondary wavelets Draw a surface w_(2) which is tangential to all these secondary wavelets. w_(2) is the wavefront at time 't+Deltat'. Huygen proved the laws of reflection and laws of refraction using concept of wavefronts. A point source of light is placed at origin, in air. The equation of wave front of the wave at time t, emitted by source at t=0, is (take refractive index of air as 1 )

(i) Define term wavefront. State Huygen.s principle. (ii) consider a plane wavefront incident on a thin convex lens. Draw a proper diagram to show him the incident wavefront traverses throught the lens and after refraction focuses on the focal point of the lens, giving the shape of the emergent wavefront. (iii) When light travels from a rarer to a denser medium, it loses speed. Does, this loss imply a reduction in energy carried by the light waves.

Huygen was the figure scientist who proposed the idea of wave theory of light he said that the light propagates in form of wavelengths. A wavefront is a imaginary surface of every point of which waves are in the same. phase. For example the wavefront for a point source of light is collection of concentric spheres which have centre at the origin w_(1) is a wavefront w_(2) is another wavefront. The radius of the wavefront at time 't' is 'ct' in thic case where 'c' is the speed of light the direction of propagation of light is perpendicular to the surface of the wavelength. the wavefronts are plane wavefronts in case of a parallel beam of light. Huygen also said that every point of the wavefront acts as the source of secondary wavelets. The tangent drawn to all secondary wavelets at a time is the new wavefront at that time. The wavelets are to be considered only in the forward direction (i.e., the direction of propagation of light) and not in the reverse direction if a wavefront w_(1) and draw spheres of radius 'cDeltat' they are called secondary wavelets. Draw a surface w_(2) which is tangential to all these secondary wavelets w_(2) is the wavefront at time t+Deltat Huygen proved the laws of reflection and laws of refraction using concept of wavefront. Q. Certain plane wavefronts are shown in figure the refractive index of medius is

Huygen was the figure scientist who proposed the idea of wave theory of light he said that the light propagates in form of wavelengths. A wavefront is a imaginary surface of every point of which waves are in the same. phase. For example the wavefront for a point source of light is collection of concentric spheres which have centre at the origin w_(1) is a wavefront w_(2) is another wavefront. The radius of the wavefront at time 't' is 'ct' in thic case where 'c' is the speed of light the direction of propagation of light is perpendicular to the surface of the wavelength. the wavefronts are plane wavefronts in case of a parallel beam of light. Huygen also said that every point of the wavefront acts as the source of secondary wavelets. The tangent drawn to all secondary wavelets at a time is the new wavefront at that time. The wavelets are to be considered only in the forward direction (i.e., the direction of propagation of light) and not in the reverse direction if a wavefront w_(1) and draw spheres of radius 'cDeltat' they are called secondary wavelets. Draw a surface w_(2) which is tangential to all these secondary wavelets w_(2) is the wavefront at time t+Deltat Huygen proved the laws of reflection and laws of refraction using concept of wavefront. Q. Plane are incident on a spherical mirror as shown in the figure. the reflected wavefronts will be

Huygen was the figure scientist who proposed the idea of wave theory of light he said that the light propagates in form of wavelengths. A wavefront is a imaginary surface of every point of which waves are in the same. phase. For example the wavefront for a point source of light is collection of concentric spheres which have centre at the origin w_(1) is a wavefront w_(2) is another wavefront. The radius of the wavefront at time 't' is 'ct' in thic case where 'c' is the speed of light the direction of propagation of light is perpendicular to the surface of the wavelength. the wavefronts are plane wavefronts in case of a parallel beam of light. Huygen also said that every point of the wavefront acts as the source of secondary wavelets. The tangent drawn to all secondary wavelets at a time is the new wavefront at that time. The wavelets are to be considered only in the forward direction (i.e., the direction of propagation of light) and not in the reverse direction if a wavefront w_(1) and draw spheres of radius 'cDeltat' they are called secondary wavelets. Draw a surface w_(2) which is tangential to all these secondary wavelets w_(2) is the wavefront at time t+Deltat Huygen proved the laws of reflection and laws of refraction using concept of wavefront. Q. Plane are incident on a spherical mirror as shown in the figure. the reflected wavefronts will be

Huygen was the figure scientist who proposed the idea of wave theory of light he said that the light propagates in form of wavelengths. A wavefront is a imaginary surface of every point of which waves are in the same. phase. For example the wavefront for a point source of light is collection of concentric spheres which have centre at the origin w_(1) is a wavefront w_(2) is another wavefront. The radius of the wavefront at time 't' is 'ct' in thic case where 'c' is the speed of light the direction of propagation of light is perpendicular to the surface of the wavelength. the wavefronts are plane wavefronts in case of a parallel beam of light. Huygen also said that every point of the wavefront acts as the source of secondary wavelets. The tangent drawn to all secondary wavelets at a time is the new wavefront at that time. The wavelets are to be considered only in the forward direction (i.e., the direction of propagation of light) and not in the reverse direction if a wavefront w_(1) and draw spheres of radius 'cDeltat' they are called secondary wavelets. Draw a surface w_(2) which is tangential to all these secondary wavelets w_(2) is the wavefront at time t+Deltat Huygen proved the laws of reflection and laws of refraction using concept of wavefront. Q. Certain plane wavefronts are shown in figure the refractive index of medius is

Huygen was the figure scientist who proposed the idea of wave theory of light he said that the light propagates in form of wavelengths. A wavefront is a imaginary surface of every point of which waves are in the same. phase. For example the wavefront for a point source of light is collection of concentric spheres which have centre at the origin w_(1) is a wavefront w_(2) is another wavefront. The radius of the wavefront at time 't' is 'ct' in thic case where 'c' is the speed of light the direction of propagation of light is perpendicular to the surface of the wavelength. the wavefronts are plane wavefronts in case of a parallel beam of light. Huygen also said that every point of the wavefront acts as the source of secondary wavelets. The tangent drawn to all secondary wavelets at a time is the new wavefront at that time. The wavelets are to be considered only in the forward direction (i.e., the direction of propagation of light) and not in the reverse direction if a wavefront w_(1) and draw spheres of radius 'cDeltat' they are called secondary wavelets. Draw a surface w_(2) which is tangential to all these secondary wavelets w_(2) is the wavefront at time t+Deltat Huygen proved the laws of reflection and laws of refraction using concept of wavefront. Q. Wavefronts incident on an interface between the media are shown in the figure. the refracted wavefront will be as shown in

Huygen was the figure scientist who proposed the idea of wave theory of light he said that the light propagates in form of wavelengths. A wavefront is a imaginary surface of every point of which waves are in the same. phase. For example the wavefront for a point source of light is collection of concentric spheres which have centre at the origin w_(1) is a wavefront w_(2) is another wavefront. The radius of the wavefront at time 't' is 'ct' in thic case where 'c' is the speed of light the direction of propagation of light is perpendicular to the surface of the wavelength. the wavefronts are plane wavefronts in case of a parallel beam of light. Huygen also said that every point of the wavefront acts as the source of secondary wavelets. The tangent drawn to all secondary wavelets at a time is the new wavefront at that time. The wavelets are to be considered only in the forward direction (i.e., the direction of propagation of light) and not in the reverse direction if a wavefront w_(1) and draw spheres of radius 'cDeltat' they are called secondary wavelets. Draw a surface w_(2) which is tangential to all these secondary wavelets w_(2) is the wavefront at time t+Deltat Huygen proved the laws of reflection and laws of refraction using concept of wavefront. Q. The wavefrot of a light beam is given by the equation x+2y+3z=c (where c is arbitrary constant) then the angle made by the direction of light with the y-axis is

Assertion: Three waves of equal amplitudes interfere at a point. Phase difference between two successive waves is pi/2 . Then, resultant intensity is same as the intensity due to individual wave. Reason: Two different light sources are never coherent.

AAKASH SERIES-WAVES OPTICS-EXERCISE -IA (DIFFRACTION)
  1. Which of the following statements is correct

    Text Solution

    |

  2. Bright colours exhibited by spider.s web, exposed to sunlight are due ...

    Text Solution

    |

  3. A plane wavefront is divided into a number of half period zones as per...

    Text Solution

    |

  4. Which element is the lightest of all other solid elements ?

    Text Solution

    |

  5. Two point sources of sound are kept at a separation of 10 cm. They vib...

    Text Solution

    |

  6. When a beam of light is used to determine the position of an object, t...

    Text Solution

    |

  7. In Fresnel.s diffraction wavefront must be

    Text Solution

    |

  8. The source is at some distance from an obstacle. Distance between obst...

    Text Solution

    |

  9. A very small opaque disc is placed in the path oa a monochromatic ligh...

    Text Solution

    |

  10. A diffraction pattern is obtained using a beam of red light. What happ...

    Text Solution

    |

  11. In a diffraction pattern the width of any fringe is

    Text Solution

    |

  12. Yellow light is used in a single slit diffraction experiment with a sl...

    Text Solution

    |

  13. In diffraction froma a single -slit, the angular width of the centre m...

    Text Solution

    |

  14. The correct relation between limit of resolution and resolving power i...

    Text Solution

    |

  15. The resolving power of electron microscope is

    Text Solution

    |

  16. The limit of resolution of eye is approximately

    Text Solution

    |

  17. The angular resolution of the telescope is determined by the

    Text Solution

    |

  18. In telescope of objective diameter (2a), the radius of the central bri...

    Text Solution

    |

  19. For better resolution, a telescope must have a

    Text Solution

    |

  20. What will be ratio (D"/"f) in microscope where, D is the diameter of t...

    Text Solution

    |