A bi-convex lens has a radius of curvature fo | vedclass

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

Question

(B) The power of a lens is given by $P = \frac{1}{f} = (\mu - 1) \left( \frac{1}{R_1} - \frac{1}{R_2} \right)$.For a bi-convex lens,$R_1 = R$ and $R_2

Vedclass · Accepted Answer

$1/5 \ cm$ and $1/7 \ cm$

Vedclass · Answer

(B) The power of a lens is given by $P = \frac{1}{f} = (\mu - 1) \left( \frac{1}{R_1} - \frac{1}{R_2} ight)$.For a bi-convex lens,$R_1 = R$ and $R_2 = -R$,so $\frac{1}{f} = (\mu - 1) \left( \frac{1}{R} - \frac{1}{-R} ight) = (\mu - 1) \frac{2}{R}$.Given $R = 1/6 \ cm$,the power is proportional to $\frac{2}{R} = 2 	imes 6 = 12 \ cm^{-1}$.For the new lens,we need $\frac{1}{R_1} + \frac{1}{R_2} = \frac{2}{R} = 12$.Checking the options:For option $C$: $R_1 = 1/3 \ cm$ and $R_2 = 1/7 \ cm$,we get $\frac{1}{R_1} + \frac{1}{R_2} = 3 + 7 = 10 
eq 12$.Wait,let's re-evaluate: $\frac{1}{R_1} + \frac{1}{R_2} = 12$.For option $B$: $R_1 = 1/5 \ cm$ and $R_2 = 1/7 \ cm$,we get $5 + 7 = 12$.Thus,the correct combination is $R_1 = 1/5 \ cm$ and $R_2 = 1/7 \ cm$.

$A$ bi-convex lens has a radius of curvature for both surfaces equal to $1/6 \ cm$. If this lens is to be replaced by another convex lens having different radii of curvature on both sides $(R_1 \neq R_2)$,without any change in the lens power,then the possible combination of $R_1$ and $R_2$ is:

Similar Questions

If the refractive index from air to glass is $\frac{3}{2}$ and that from air to water is $\frac{4}{3}$,then the ratio of focal lengths of a glass lens in water and in air is

$A$ thin lens made of glass of refractive index $1.5$ has a front surface $+ 11 D$ power and back surface $-6 D.$ If this lens is submerged in a liquid of refractive index $1.6,$ the resulting power of the lens is

At what distance from a convex lens of focal length $30 \ cm$, an object should be placed so that the size of the image is $1/2$ of the object (in $cm$)?

$A$ convex lens of focal length $30 \,cm$ produces $5$ times magnified real image of an object. What is the object distance (in $\,cm$)?

What are paraxial rays?

Vedclass Test Series

Exam Paper Generator

Online Exam Module