The ray diagram shown could be correct:

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

Question

(C) The ray diagram shows a convex lens causing incident parallel rays to diverge after passing through it. This indicates that the convex lens is beh

Vedclass · Accepted Answer

If ${n_1} = {n_2}$ and ${n_1} > {n_g}$

Vedclass · Answer

(C) The ray diagram shows a convex lens causing incident parallel rays to diverge after passing through it. This indicates that the convex lens is behaving like a concave lens. According to the lens maker's formula,the focal length $f$ of a lens in a medium is given by $\frac{1}{f} = (\frac{n_g}{n_m} - 1)(\frac{1}{R_1} - \frac{1}{R_2})$. When the surrounding medium refractive index $n_m$ (here $n_1 = n_2 = n_m$) is greater than the refractive index of the lens material $n_g$,the term $(\frac{n_g}{n_m} - 1)$ becomes negative. Consequently,the focal length $f$ becomes negative,and the convex lens behaves as a diverging (concave) lens. Therefore,the condition for this behavior is $n_1 = n_2$ and $n_1 > n_g$.

Similar Questions

If ${I_1}$ and ${I_2}$ are the sizes of the images for the two positions of the lens in the displacement method,then the size of the object is given by:

$A$ convex lens is used to form an image of an object on a screen. If the upper half of the lens is blackened,so that it becomes opaque,then

$A$ glass convex lens $(\mu_{g}=1.5)$ has a focal length of $8 \ cm$ when placed in air. What would be the focal length of the lens in $cm$ when it is immersed in water $(\mu_{w}=\frac{4}{3})$?

$A$ plano-convex lens has a diameter of $6\, cm$ and a thickness of $3\, mm$ at the center. If the speed of light in the material of the lens is $2 \times 10^{8}\, m/s$,then the focal length of the lens is ..... $cm$.

$A$ convex lens $T$ is used to form an image whose size is one-fourth that of the size of the object. Then the object distance is (in $f$)

Vedclass Test Series

Exam Paper Generator

Online Exam Module