An object 20 cm from a concave mirror form an image, double the size of the object, on a screen. How far should the screen be placed from the mirror?

-40 cm

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

40 cm

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

20 cm

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

-20 cm

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

30 cm

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

Open in App

Solution

The correct option is A -40 cm
Here $u = - 20 c m, m = - 2$ Now, $m = \frac{- v}{u} ⟹ - 2 = \frac{v}{20} ⟹ v = - 40$

Suggest Corrections

Similar questions

A concave mirror forms an image of 20 cm high object on a screen placed 5.0 m away from the mirror. The height of the image is 50 cm. Find the focal length of the mirror and the distance between the mirror and the object.

An object 4 cm in size is placed at a distance of 25 cm from a concave mirror of focal length 15 cm. At what distance from the mirror should the screen be kept so that a sharp image of the object can be obtained on screen? Find the nature and height of the image.

Q. How far should an object be kept from the concave mirror of focal length 20 cm to form a real image one-fifth of its size?

an object of size 5cm is placed at 30cm infront of a concave mirror of focal length 20cm .At what distance should a screen be placed so that a sharp image formed on it? determine the nature and size.

Q. An object of size 7 cm is placed at 27 cm in front of a concave mirror of focal length 18 cm. At what distance from the mirror should a screen be placed, so that a sharp focused image can be obtained ? Find the size and the nature of the image.

Join BYJU'S Learning Program

An object 20 cm from a concave mirror form an image, double the size of the object, on a screen. How far should the screen be placed from the mirror?

The correct option is A -40 cmHere u=−20cm, m=−2 Now, m=−vu⟹−2=v20⟹v=−40

The correct option is A -40 cm
Here $u = - 20 c m, m = - 2$ Now, $m = \frac{- v}{u} ⟹ - 2 = \frac{v}{20} ⟹ v = - 40$