Pankaj Bhatt Solutions for Chapter: Refraction Through a Lens, Exercise 3: QUESTIONS

Copy the figure and complete it to show the formation of image of the object AB. Name the lens used.

The focal length of a convex lens and a concave mirror both is $20 \mathrm{cm}$. What would be the change in their focal lengths if the two are immersed in water?

Two thin lenses of focal lengths $+20 \mathrm{cm}$ and $-30 \mathrm{cm}$ are put in contact. What is the focal length of the combination? What is the power of combination?

An object of height $5 \mathrm{cm}$ is placed at a distance of $10 \mathrm{cm}$ from a convex lens of focal length $15 \mathrm{cm}$. Use an appropriate scale and draw a ray diagram to obtain the image of the object. What is the size of the image? 

An object of height $5 \mathrm{cm}$ is placed at a distance of $15 \mathrm{cm}$ in front of a concave lens of focal length $10 \mathrm{cm}$. Use an appropriate scale and draw a ray diagram to obtain the image of the object. What is the size of the image? 

Draw the ray diagram to show the image formation through a hand lens. Write formula for its magnification. 

The figure shows a convex  and a concave lens of focal lengths $+20 \mathrm{cm}, -30 \mathrm{cm}$ respectively, their lenses in contact. What is the power of each lens? What is the focal length of the combined lens?

Figure shows a point source of light $20 \mathrm{cm}$ in front of a convex lens of focal length $10 \mathrm{cm}$. What is the final position of the image? Show by a ray diagram.