Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NEET2008PhysicsRay OpticsActual

Two thin lenses of focal lengths f₁ and f₂ are in contact and coaxial. The power of the combination is

Options

  1. Af₁ f₂
  2. Bf₂ f₁
  3. Cf₁+f₂ f₁ f₂
  4. Df₁+f₂ f₁ f₂

Correct answer

D. f₁+f₂ f₁ f₂

Step-by-step solution

If two thin lenses of focal lengths f₁, f₂ are placed in contact coaxially, then equivalent focal length of combination is 1 F = 1 f₁ + 1 f₂ - 0 f₁ f₂ = 1 f₁ + 1 f₂ Power for the combination is P= 1 F = 1 f₁ + 1 f₂ = f₁+f₂ f₁ f₂

Practice Ray Optics on Quantrex Academy →

More from Ray Optics

A container is filled with water ( = 4/3 ) up to a height of 24 cm. A concave mirror is placed 10 cm above the water level, and the image (I) of an object placed at the bottom is f 2026The refracting angle of a prism is 'A' and its refractive index is ( A 2 ) . The minimum deviation produced by the prism is 2026A circular beam of light having diameter 'd' falls on a plane liquid surface from air. The angle of incidence is 45^ and refractive index of liquid is 'n'. The diameter of the refr 2026What is the total optical path length of two media in contact with thicknesses of d and d 4 and refractive indices of n₁ and n₂ , respectively? 2026A beam of white light is allowed to pass through convex lens parallel to principal axis, the different colours of light converge at different points on the principle axis after ref 2026The angle of minimum deviation produced by a thin prism in air is ₁ . What will be the minimum deviation ( ₂) if the prism is immersed in another liquid medium? _a n_g = 3/2, _a n_ 2026A ray of light passes through four transparent media with refractive indices ₁ , ₂ , ₃ and ₄ as shown in the figure. The surfaces of all media are parallel. If the emergent ray CD 2026The thin prism having refracting angle 10^ is made of glass of refractive index 1.42 . This prism is combined with another thin prism of glass of refractive index 1.7 . This combin 2026 Full Ray Optics list All NEET PYQs