An astronomical telescope has a large aperture to

Which of the following is not due to total internal reflection?

Direction: Each question contains STATEMENT-1 and STATEMENT-2. Choose the correct answer(ONLY ONE option is correct ) from the following-

Statement 1 :If P₁ and P₂ be the powers of two thin lenses located coaxially in a medium of refractive index µat a distance d, then the power P of the combination is P = P₁ + P₂ – P₁P₂d/µ

Statement 2 : Because for above given system equivalent focal length is given by \(F=\frac{f_{1}f_{2}}{f_{1}+f_{2}-d/\, \mu }\) and P = ¹⁄_F

Direction: Each question contains STATEMENT-1 and STATEMENT-2. Choose the correct answer(ONLY ONE option is correct ) from the following-

Statement 1: Optical fibres are used to transmit light without any appreciable loss in its intensity over distance of several kilometers.

Statement 2: Optical fibres are very thick and all the light is passed through it without any loss.

Direction: Each question contains STATEMENT-1 and STATEMENT-2. Choose the correct answer(ONLY ONE option is correct ) from the following-

Statement 1: Critical angle is minimum for violet colour.

Statement 2 : Because critical angle \(\theta _{c}=sin^{-1}\left ( \frac{1}{\mu } \right )\) and μ α ¹⁄_λ

Direction: Each question contains STATEMENT-1 and STATEMENT-2. Choose the correct answer(ONLY ONE option is correct ) from the following-

Statement 1: Two convex lenses joined together can not produce an achromatic combination.

Statement 2: The condition for achromatism is \(\frac{\omega _{1}}{f_{1}}+\frac{\omega _{2}}{f_{2}}=0\) where symbols have their usual meaning.

For a given lens, the magnification was found to be twice as large as when the object was 0.15 m distant from it as when the distance was 0.2 m. The focal length of the lens is

The graph between angle of deviation (δ) and angle of incidence (i) for a triangular prism is represented by

For a normal eye, the cornea of eye provides a converging power of 40D and the least converging power of the eye lens behind the cornea is 20D. Using this information, the distance between the retina and the eye lens of the eye can be estimated to be

A plano convex lens fits exactly into a plano concave lens.Their plane surfaces are parallel to each other. If lenses are made of different materials of refractive indices m₁ and m₂ and R is the radius of curvature of the curved surface of the lenses, then the focal length of the combination is