#spherical wave

Optical Phenomena and Applications

What is the shape of the wavefront reflected by a plane mirror when a spherical wave is incident on it?

**Convex lens focusing** plane wave into point because lens introduces phase delay proportional to thickness, converting plane wavefront to spherical converging to focal point, property ensures rays parallel to axis meet at focus, spherical aberration minimized for paraxial rays, lensmaker's formula determines focal length. A spherical wavefront incident on a plane mirror reflects as a spherical wavefront, diverging from the mirror’s virtual focus. Using Δ = d sinθ, y = n λ D/d, a sinθ = n λ, I = I₀ cos²θ, n = c/v, sinC = 1/n, λ' = λ/n and A = 2a cos(φ/2), calculation gives Spherical, illustra

Ref: NCERT > Physics Book > Wave Optics > Optical Phenomena and Applications

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Wavefront and Huygens Principle

What characteristic of light waves allows a convex lens to transform a plane wave into a converging spherical wave?

**Wavefront** is locus of points in same phase, spherical from point source, plane at large distance because radius large, Huygens principle every point on wavefront acts as secondary source of wavelets, new wavefront envelope of secondary wavelets, allows prediction of new wavefront shape from known wavefront, explains reflection and refraction. The wave nature enables the lens to delay the wavefront variably across its surface, curving it into a spherical shape that converges at the focal point. Using Δ = d sinθ, y = n λ D/d, a sinθ = n λ, I = I₀ cos²θ, n = c/v, sinC = 1/n, λ' = λ/n and

Ref: NCERT > Physics Book > Wave Optics > Wavefront and Huygens Principle

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Wavefront and Huygens Principle

What is the shape of the wavefront produced by a point source in a uniform medium?

**Wavefront types** point source spherical, distant point source plane, after convex lens plane wave focuses to point because lens adds phase delay proportional to thickness, converging spherical wavefront, after concave mirror plane wave becomes spherical converging to focus, illustrating Huygens construction. A point source emits waves uniformly in all directions, producing spherical wavefronts in a medium where the speed is isotropic. Using Δ = d sinθ, y = n λ D/d, a sinθ = n λ, I = I₀ cos²θ, n = c/v, sinC = 1/n, λ' = λ/n and A = 2a cos(φ/2), calculation gives Spherical, illustrating interf

Ref: NCERT > Physics Book > Wave Optics > Wavefront and Huygens Principle

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Wavefront and Huygens Principle

What is the shape of the wavefront emitted by a point source in a uniform medium close to the source?

**Huygens principle** predicts shape of wavefront after propagation, for point source close spherical, far plane, after reflection from plane mirror spherical wave becomes spherical with centre mirrored, plane wave remains plane but direction changes angle of incidence equals reflection, after passing through thin prism plane wavefront tilts due to different path. A point source in a uniform medium emits spherical wavefronts, especially close to the source. Using Δ = d sinθ, y = n λ D/d, a sinθ = n λ, I = I₀ cos²θ, n = c/v, sinC = 1/n, λ' = λ/n and A = 2a cos(φ/2), calculation gives Spherical,

Ref: NCERT > Physics Book > Wave Optics > Wavefront and Huygens Principle

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Wavefront and Huygens Principle

What is the shape of the wavefront emitted by a point source at a large distance?

**Wavefront** is locus of points in same phase, spherical from point source, plane at large distance because radius large, Huygens principle every point on wavefront acts as secondary source of wavelets, new wavefront envelope of secondary wavelets, allows prediction of new wavefront shape from known wavefront, explains reflection and refraction. At a large distance from a point source, the spherical wavefront appears plane over a small region. Using Δ = d sinθ, y = n λ D/d, a sinθ = n λ, I = I₀ cos²θ, n = c/v, sinC = 1/n, λ' = λ/n and A = 2a cos(φ/2), calculation gives Plane, illustrating int

Ref: NCERT > Physics Book > Wave Optics > Wavefront and Huygens Principle

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