Single Choice

A point source is placed on the axis of a symmetrical convex lens of focal length $$20\ cm$$ at a distance $$40\ cm$$. If lens is raised by $$1\ cm$$, by how much will the image be lifted relative to the previous axis ?

A$$1\ cm$$
B$$3\ cm$$
C$$2\ cm$$
Correct Answer
D$$4\ cm$$

Solution

SIMILAR QUESTIONS

Optics

The refractive index of a lens material is $$\mu$$ and focal length $$fd$$. Due to some chemical changes in the material, its refractive index has increased by $$2\%$$. The percentage decrease, in focal length for $$\mu=1.5$$ will be :

Optics

A source of light is located at a distance $$ l=90 \mathrm{cm} $$ from a screen. A thin converging lens provides the sharp image of the source when placed between the source of light and the screen at two positions. Determine the focal length of the lens if (b) the transverse dimensions of the image at one position of the lens are $$ \eta=4.0 $$ greater than those at the other position.

Optics

Will the focal length of a lens for red light be more, same or less than that for blue light ?

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