Embibe Experts Solutions for Exercise 5: EXERCISE 9.5

A thin convex lens of focal length $20 \mathrm{cm}$ is kept in contact with a plane mirror. The focal length of the combination will be

Two lens of power $+4D$ and $-2D$ are placed in contact to form an achromatic doublet. The ratio of their dispersive power is

A lens made of glass of refractive index $1.5$ has focal length $25 \mathrm{cm}$. Its focal length in water will be $\left[{\mu }_{\mathrm{w}}=\frac{4}{3}\right]$

A concave mirror of focal length $30 \mathrm{cm}$ in air is immersed in water $\left[\mu =\frac{4}{3}\right]$. The focal length of the mirror in water will be

When a thin plano-convex lens $(\mu =1.5)$ polished from its plane surface behave like a concave mirror of focal length $40 \mathrm{cm}$. The radius of curvature of the lens is

A thin convex lens of focal length $20 \mathrm{cm}$ is split into parts as shown in figure. An object $O$ is placed at distance $10 \mathrm{cm}$ from the lens. The distance between two virtual images of object will be