Home
Class 11
PHYSICS
A screen is placed a distance 40 cm away...

A screen is placed a distance 40 cm away from an illuminated object. A converging lens is placed between the source and the screen and it is attempted to form the image of the source on the screen. If no position could be found, the focal length of the lens

A

must be less than 10cm

B

must be greater than 20cm

C

must not be greater than 20cm

D

must not be less than 10cm

Text Solution

Verified by Experts

The correct Answer is:
D
Promotional Banner

Similar Questions

Explore conceptually related problems

(a) A screen is kept at a distance of 1m from the object. A converging lens between the object and the screen, when placed at any of the two positions which are 60cm apart, forms a sharp image of the object on the screen. Find the focal length of the lens. (b) In the two positions of the lens, lateral size of the image is 4cm and 9cm. Find the size of the object.

A luminous object is separated from a screen by distance d. A convex lends is placed between the object and the screeen such that it forms a distinct image on the screen. The maximum possible focal length of this convex lens is.

A luminous object is separated from a screen by distance d. A convex lends is placed between the object and the screeen such that it forms a distinct image on the screen. The maximum possible focal length of this convex lens is.

In the displacement method , a convex lens is placed in between an object and a screen . If one of them magnification is 3 and the displacement of the lens between the two positions is 24 cm , then the focal length of the lens is :-

An object is placed 50cm from a screen as shown in figure. A converging lens is moved such that line MN is its principal axis. Sharp images are formed on the screen in two positions of lens separated by 30cm. Find the focal length of the lens in cm.

A convex lens is placed some where between an object and a screen which are separated by 48 cm. If the numerical value of magnification produced by the lens is 3, what is the focal length of lens?

A luminous object and a screen are at a fixed distance D apart. A converging lens of focal length f is placed between the object and screen. A real image of the object in formed on the screen for two lens positins if they are separated by a distance d equal to

An object is placed at a distance of 1.5 m from a screen and a convex lens is interposed between them. The magnification produced is 4 . What is the focal length of the lens ?

A convex lens produces an image of a condle flame upon a screen whose distance from candle is D. When the lens is displaced through a distance x , (the distance between the candle and the screen is kept constant), it is found that a sharp image is again produced upon the screen. Find the focal length of the lens in terms of D and x .

A convex lens is used to throw on a screen 10 m from the lens, a magnified image of an object. If the magnification is to be 19 , find the focal length of the lens.