A compound microscope uses an objective lens of focal length 4 cm and eyepiece lens of focal length 10 cm. An object is placed at 6 cm from the objective lens. Calculate the magnifying power of the compound microscope. Also calculate the length of the microscope.

An astronomical refractive telescope has an objective of focal length 20 m and an eyepiece of focal length 2 cm.

A small telescope has an objective lens of focal length 140 cm and an eyepiece of focal length 5.0 cm. what is the separation between the objective lens and the eyepiece?

A person with a normal near point (25 cm) using a compound microscope with objective of focal length 8.0 mm and an eyepiece of focal length 2.5cm can bring an object placed at 9.0mm from the objective in sharp focus. What is the separation between the two lenses? Calculate the magnifying power of the microscope.

An astronomical telescope has an objective lens of focal length 20 m and eyepiece of focal length 1 cm. Find the angular magnification of the telescope.

A convex lens of focal lenth 30 cm and a concave lens of focal length 60 cm are placed in contact.Find the power of the combination.

A compound microscope consists of an objective lens of focal length 2.0 cm and an eyepiece of focal length 6.25 cm separated by a distance of 15 cm. How far from the objective should an object be placed in order to obtain the final image at the least distance of distinct vision (25 cm)? What is the magnifying power of the microscope in?

A compound microscope with an objective of 1.0 cm focal length and an eye-piece of 2.0 cm focal length has a tube of lengh of 20 cm.Calculate the magnifying power of the microscope,if the final image is formed at the near point of the eye.