In displacement method we use a lens of focal length $f$ and distance between object and screen is $60 c m$ Possible value for focal length is

- 15 c m

No worries! We‘ve got your back. Try BYJU‘S free classes today!

30 c m

No worries! We‘ve got your back. Try BYJU‘S free classes today!

12 c m

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

20 c m

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is C $12 c m$
We know that
Max possible focal length
$4 \times f_{m a x} = D$
$f = \frac{D}{4}$
$= \frac{60}{4} = 15$
so $f$ should be less than $15$
$s o = 12 c m$

Suggest Corrections

Similar questions

Q. Which of the following options is /are correct regarding the Lens- displacement method.

[D = distance between object and screen, f = focal length of lens]

Q. A combination of two thin lenses with focal lengths

f_{1}

and

f_{2}

respectively forms an image of distant object at distance 60 cm when lenses are in contact. The position of this image shifts by 30 cm towards the combination when two lenses are separated by 10 cm. The corresponding values of

f_{1}

and

f_{2}

are

Q. A convex lens of focal length

f

is placed somewhere in between the object and a screen. The distance between object and screen is

x

. If magnification produced is

m

, the focal length of the lens is:

Q. Flat surface of a plano-convex lens of focal length 20 cm is silvered. If object is placed at 60 cm from lens then distance of image from lens is

A convex lens of focal length f is placed somewhere in between an object and a screen. The distance between the object and the screen is x. If the numerical value of the magnification produced by the lens is m, then the focal length of the lens is

Join BYJU'S Learning Program

In displacement method we use a lens of focal length f and distance between object and screen is 60 cm Possible value for focal length is

The correct option is C 12 cmWe know thatMax possible focal length 4×fmax=Df=D4=604=15so f should be less than 15so=12 cm

In displacement method we use a lens of focal length $f$ and distance between object and screen is $60 c m$ Possible value for focal length is

The correct option is C $12 c m$
We know that
Max possible focal length
$4 \times f_{m a x} = D$
$f = \frac{D}{4}$
$= \frac{60}{4} = 15$
so $f$ should be less than $15$
$s o = 12 c m$