Home
Class 12
PHYSICS
A microscope consisting of two convex le...

A microscope consisting of two convex lenses of focal lengths 2 cm and 5 cm placed 20 cm apart. Where must the object be placed so that the final image (virtual) is at a distance of 25 cm from eye ?

Text Solution

Verified by Experts

For the eyepiece, focal length
`f=f_(e)=+5cm,v=v_(e)=-25cm,u=u_(e)="` substituting in
`1/f=1/v-1/u, 1/5=1/(-25) -1/u_(e)`
`1/u_(e)=(-6)/25`
`u_(e)=- 26/6 cm`
object for the eyepiece is to be at a distance of `25/6` A m to its left.
But `v_(0)+u_(e)=20cm` where `u_(e)=25/6 cm`
`v_(0)=20-u_(e)=95/6cm`
For the objective, `v=v_(0)=+95/6 cm`
`f=f_(0)=+2cm,u=?`
`1/2=6/95-1/u`
`1/u=83/190,u=-190/83=-2.29cm`
The object is to be placed at a distance of 2.29cm to the left side of the objective.
Promotional Banner

Topper's Solved these Questions

  • RAY OPTICS AND OPTICAL INSTRAUMENTS

    NARAYNA|Exercise CUQ (REFLECTION)|9 Videos

  • RAY OPTICS AND OPTICAL INSTRAUMENTS

    NARAYNA|Exercise CUQ (REFRECTION)|28 Videos

  • NUCLEI

    NARAYNA|Exercise ASSERTION & REASON|5 Videos

  • SEMI CONDUCTOR DEVICES

    NARAYNA|Exercise Level-II (H.W)|36 Videos

Similar Questions

Explore conceptually related problems

A compound microscope has an objective of focal length 2 cm and eye-piece of focal length 5 cm. The distance between the two lenses is 25 cm. If the final image is at a distance of 25 cm from the eye-piece, find the magnifying power of the microscope. What would be the magnifying power if the microscope were reversed ?

Two plano-convex lenses of focal lengths 20cm and 30cm are placed together to form a double convex lens. The final focal length will be

An optical system consists of a thin convex lens of focal length 30 cm and a plane mirror placed 15 cm behind the lens. An object is placed 15 cm in front of the lens. The distance of the final image from the object is

A compound microscope has an objective lens of 1.0 cm focal length and an eye-piece of 2.5 cm of focal length. When the object is placed at 1.1 cm from the objective, the final image is at the least distance of direct vision. Thus, the magnification produced is

An optical system consists of two convergent lenses with focal length f_1=20 cm and f_2=10 cm. The distance between the lenses is d=30 cm. An object is placed at a distance of 30 cm from the first lens. At what distance from the second lens will the images be obtained ?

The two lenses of a compound microscope are of focal lengths 2 cm and 5 cm. If an object is placed at a distance of 2.1 cm from (he objective of focal length 2 cm the final image forms at the least distance of distinct vision of a normal eye. Find the distance between the objective and eyepiece

The two lenses of a compound microscope are of focal lengths 2 cm and 5 cm. If an object is placed at a distance of 2.1 cm from the objetive of focal length 2 cm the final image forms at the least distance of distinct vision of a normal eye. Find the frnagnifying powerjof the microscope