From the relation OI=uv Here, O=1.39×109,v=0.1 m, u∴I=1.5×1011 m=1.5×10110.1×1.39×109=9.2×10−4 m
A boy is trying to start a fire by focusing sunlight on a piece of paper using an equiconvex lens of focal length 10 cm. The diameter of the sun is 1.39×109 m and its mean distance from the earth is 1.5×1011 m. What is the diameter of the sun's image on the paper?
Held on 30 Apr 2008 · Verified 9 Jul 2026.
9.2×10−4 m
6.5×10−4 m
6.5×10−5 m
12.4×10−4 m
Sign in to track your attempts and accuracy.
Sign in to keep a private note on this question. Nothing you write is ever public.
The refractive index of glass is 1.5. The speed of light in glass is:
Two thin lenses of focal lengths f₁ = +20 cm and f₂ = -10 cm are in contact. The power of the combination is:
In a certain camera, a combination of four similar thin convex lenses are arranged axially in contact. Then the power of the combination and the total magnification in comparison to the power $(p)$ and magnification $(m)$ for each lens will be, respectively
The intensity of transmitted light when a polaroid sheet, placed between two crossed polaroids at $22.5^{\circ}$ from the polarization axis of one of the polaroid, is ( $\mathrm{I}_0$ is the intensity of polarised light after passing through the first polaroid):
A microscope has an objective of focal length 2 cm , eyepiece of focal length 4 cm and the tube length of 40 cm . If the distance of distinct vision of eye is 25 cm , the magnification in the microscope is :
Work through every NEET UG Optics PYQ, year by year.