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

Question

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

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 :-
A. 10 cm
B. 9 cm
C. 6 cm
D. 16/3cm

Monjur Alahi

5 views

2025-01-04 04:42

1 Answers

Related Questions

A convex lens forms an image of an object on a screen 30 cm from the lens. When the lens is moved 90 cm towards the object, then the image is again fo

2 Answers 14 Views

The distance between an object and a divergent lens is m times the focal length of the lens. The linear magnification produced by the lens is

2 Answers 4 Views

A convex lens produces an image of a real object on a screen with a magnification of 1/2. When the lens is moved 30 cm away from the object, the magni

2 Answers 15 Views

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

2 Answers 5 Views

An object is placed 30cm away from a convex lens of focal length 10cm and a sharp image is formed on a screen. Now, a convex lens is placed In contact

2 Answers 5 Views

The distance between object and the screen is D. Real images of an object are formed on the screen for two positions of a lens separated by a distance d. The ratio between the sizes of two images will be:

2 Answers 4 Views

A convex lens of focal length 15 cm is placed on a plane mirror. An object is placed at 30 cm from the lens. The image is

2 Answers 9 Views

A convex lens is placed between an object and a screen which are at a fixed distance apart for one position of the lens. The magnification of the imag

2 Answers 5 Views

An object and a screen are fixed at a distance d apart. When a lens of focal length f is moved between the object and the screen, sharp images of the

2 Answers 5 Views

A convex lens forms an image of an object on a screen. The height of the image is 9 cm . The lens is now displaced until an image is again obtained on

2 Answers 4 Views

Salim Ahmed Kawsar · Accepted Answer · 2023-02-05T15:29:48+06:00

Salim Ahmed Kawsar

Correct Answer - B
`X = u_(2) - u_(1) = 24`
`m = (v_(1))/(u_(1)) = 3 implies v_(1) = 3u_(1) "or" u_(2) = 3u_(1)`
`3u_(1) - u_(1) = 24 implies u_(1) = 12 "cm"`
Hence `f = (D^(2) - X^(2))/(4D) = ((48)^(2) - (24)^(2))/(4 xx 48)`
=`((48 +24) (48-24))/(4 xx 48) = (72 xx 24)/(4 xx (48)^(2)) = 9 "cm"`

5 views Answered 2023-02-05 15:29