A compound microscope consists of an objective lens of focal length 2cm and an eyepiece of focal length 6.25cm separated by a distance of 15cm. How far from the objective should an object be placed in or der to obtain the final image at infinity.

A compound microscope consists of an objective lens of focal length 2cm and an eyepiece of focal length 6.25cm separated by a distance of 15cm. How far from the objective should an object be placed in or der to obtain the final image at Least distance of distinct vision.

A small telescope has an objective lens of focal length 144 cm and eye piece of focal length 6.0 cm. What is the magnifying power of the telescope ?

Calculate the power of a lens of focal length 25 cm .

A small telescope has an objective lens of focal length 140 cm and an eyepiece of focal length 5 cm. What is the magnifying power of the telescope for viewing distant objects when the telescope is in normal adjustment.

A small telescope has an objective lens of focal length 140 cm and an eyepiece of focal length 5 cm. What is the magnifying power of the telescope for viewing distant objects when the final image is formed at the least distance of distinct vision(25cm).