A compound microscope consists of an objective lens of focal length 1 cm and an eye piece of focal length 5 cm with a separation of 10 cm.
The distance between an object and the objective lens, at which the strain on the eye is minimum is `n/40cm`. The value of n is ___________

A compound microscope has an objective lens of focal length 1 cm and an eyepiece of focal length 2.5 cm . (i) If a distinct image of an object situated at a distance of 10.5 cm from the objective is seen , the magnification will be

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 ?

A compound microscope consists of an objective of focal length 1 cm and an eye-piece of focal length 5cm . An object is placed at a distance of 0.5cm from the objective. What should be the separation between the lenses so that the microscope projects an inverted real image of the object on the screen 30 cm behind the eye-piece ?

A compound microscope consists of an object lens of focal length 2 cm and an eyepiece of focal length 5 cm. When an object is placed at 2.2 cm from the object lens, the final image is at 25 cm from the eye lens. What is the distance between the lenses ? What is the total linear magnification ?