The dispersive powers of two lenses are 0.01 | vedclass

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

Question

(A) For an achromatic combination of two thin lenses in contact,the condition is given by: $\frac{\omega_1}{f_1} + \frac{\omega_2}{f_2} = 0$,where $\o

Vedclass · Accepted Answer

Diverging lens having focal length $20\, cm$.

Vedclass · Answer

(A) For an achromatic combination of two thin lenses in contact,the condition is given by: $\frac{\omega_1}{f_1} + \frac{\omega_2}{f_2} = 0$,where $\omega_1, \omega_2$ are the dispersive powers and $f_1, f_2$ are the focal lengths of the two lenses.Given: $\omega_1 = 0.01$,$\omega_2 = 0.02$,and $f_1 = +10\, cm$.Substituting the values into the condition: $\frac{0.01}{10} + \frac{0.02}{f_2} = 0$.$\frac{0.01}{10} = -\frac{0.02}{f_2}$.$f_2 = -\frac{0.02 	imes 10}{0.01} = -20\, cm$.The negative sign indicates that the second lens must be a diverging (concave) lens with a focal length of $20\, cm$.

The dispersive powers of two lenses are $0.01$ and $0.02.$ If the focal length of one lens is $+10\, cm$,what should be the focal length of the second lens so that they form an achromatic combination?

Similar Questions

Two identical glass $(\mu_g = 3/2)$ equiconvex lenses of focal length $f$ each are kept in contact. The space between the two lenses is filled with water $(\mu_w = 4/3).$ The focal length of the combination is

$A$ plano-convex lens of refractive index $\mu_1$ fits exactly into a plano-concave lens of refractive index $\mu_2$. Their plane surfaces are parallel to each other. $R$ is the radius of curvature of the curved surface of the lenses. The focal length of the combination is:

An eye specialist prescribes spectacles having a combination of a convex lens of focal length $40\, cm$ in contact with a concave lens of focal length $25\, cm$. The power of this lens combination in diopters is

The focal length of a combination of lenses formed with lenses having powers of $+2.50 \ D$ and $-3.75 \ D$ will be:

Curved surfaces of a plano-convex lens of refractive index $\mu_{1}$ and a plano-concave lens of refractive index $\mu_{2}$ have equal radius of curvature as shown in the figure. Find the ratio of the radius of curvature to the focal length of the combined lenses.

Vedclass Test Series

Exam Paper Generator

Online Exam Module