In a Ramsden eyepiece,two planoconvex lenses, | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(C) In a Ramsden eyepiece,the two planoconvex lenses have the same focal length $f$ and are separated by a distance $d = \frac{2f}{3}$.Given the separ

Vedclass · Accepted Answer

$13.5$

Vedclass · Answer

(C) In a Ramsden eyepiece,the two planoconvex lenses have the same focal length $f$ and are separated by a distance $d = \frac{2f}{3}$.Given the separation distance $d = 12 \ cm$,we can find $f$:$d = \frac{2f}{3} \implies 12 = \frac{2f}{3} \implies f = \frac{12 	imes 3}{2} = 18 \ cm$.The equivalent focal length $f_{eq}$ of a combination of two lenses with focal lengths $f_1$ and $f_2$ separated by distance $d$ is given by:$\frac{1}{f_{eq}} = \frac{1}{f_1} + \frac{1}{f_2} - \frac{d}{f_1 f_2}$.For a Ramsden eyepiece,$f_1 = f_2 = f$ and $d = \frac{2f}{3}$.Substituting these values:$\frac{1}{f_{eq}} = \frac{1}{f} + \frac{1}{f} - \frac{2f/3}{f^2} = \frac{2}{f} - \frac{2}{3f} = \frac{6-2}{3f} = \frac{4}{3f}$.Therefore,$f_{eq} = \frac{3f}{4}$.Substituting $f = 18 \ cm$:$f_{eq} = \frac{3 	imes 18}{4} = \frac{54}{4} = 13.5 \ cm$.

In a Ramsden eyepiece,two planoconvex lenses,each of focal length $f$,are separated by a distance of $12 \ cm$. The equivalent focal length (in $cm$) of the eyepiece is:

Similar Questions

In a microscope, the objective has a focal length $f_0 = 2 \ cm$ and the eyepiece has a focal length $f_e = 4 \ cm$. The tube length is $32 \ cm$. The magnification produced by this microscope for normal adjustment is . . . . . . .

The magnifying power of a simple microscope is $6$. The focal length of its lens in metres will be,if the least distance of distinct vision is $25\,cm$.

Magnification of a compound microscope is $30$. The focal length of the eyepiece is $5 \, cm$ and the image is formed at the near point (distance of distinct vision) of $25 \, cm$. The magnification of the objective lens is:

$A$ wire mesh consisting of very small squares is viewed at a distance of $8 \, cm$ through a magnifying converging lens of focal length $10 \, cm$,kept close to the eye. The magnification produced by the lens is

$A$ simple microscope is used to see an object first in blue light and then in red light. Due to the change from blue to red light, what is the effect on its magnifying power?

Vedclass Test Series

Exam Paper Generator

Online Exam Module