Skip to content
Login Register

#mirror physics

2 public questions tagged with this topic.

Wavefront and Huygens Principle

What is the shape of the wavefront after a plane wave reflects off a plane mirror?

**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 plane wave reflecting off a plane mirror remains a plane wavefront, as the reflection preserves its flat nature. 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 interference, diffractio

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

View Details
Combination of Lenses and Lens Systems

What ensures that a convex mirror produces an image smaller than the object at all positions?

**Lens combination** effective focal length calculation uses reciprocal sum, for f₁=10 cm, f₂=20 cm in contact, 1/F=1/10+1/20=3/20, F=6.67 cm, P=15 D, stronger converging than either alone, illustrating power addition. A convex mirror diverges reflected rays, making them appear to come from a point closer to the mirror than the object. This divergence reduces the image size relative to the object, resulting in a diminished image regardless of the object’s distance from the mirror. Substituting values gives Divergence reducing image size, which matches expected image position and magnification

Ref: NCERT > Physics Book > Ray Optics > Combination of Lenses and Lens Systems

View Details