Microscope — Prelims Questions

A simple microscope uses a convex lens of focal length $5,\text{cm}$. If the final image is formed at the least distance of distinct vision ($25,\text{cm}$), what is the angular magnification?

A compound microscope has an objective lens of focal length $1,\text{cm}$ and an eyepiece of focal length $2.5,\text{cm}$. If the object is placed $1.2,\text{cm}$ from the objective, and the final image is formed at infinity, what is the length of the microscope tube?

A microscope objective has a numerical aperture of $0.6$. If light of wavelength $500,\text{nm}$ is used, what is the minimum distance between two points that can be resolved?

An objective lens of a compound microscope has a focal length of $0.5,\text{cm}$ and forms an image at $10,\text{cm}$ from it. The eyepiece has a focal length of $2,\text{cm}$. If the final image is formed at $D = 25,\text{cm}$, what is the total magnification?

Which of the following changes would increase the resolving power of a compound microscope?

To obtain a virtual, erect, and magnified image using a simple microscope (convex lens), the object must be placed: