The image of an illuminated square object is obtained on a screen with the help of a converging lens. The distance of the square from the lens is 30 cm. The area of the image is 9 times of the square. What is the focal length of the ions ?

The real iamge of a square hole in screen, illuminated be light is obtained on another screen with the help of a converging lens. This distance of the hole from the lens is 20 cm. the are of the image is nine times that of the hole. What is the focal length of the lens ?

The image of a square hole in a screen illuminated by light is obtained on another screen with the help of converging lens. The distance of the hole from the lens is 40 cm. If the area of the image is nine times that of the hole, the focal length of the lens is

An image of a bright square is obtained on a screen with the aid of a convergent lens. The distance between the square and the lens is 40cm. The area of the image is nine times larger than that of the square. Select the correct statement(s):

An image of a bright square is obtained on a screen with the aid of a convergent lens. The distance between the square and the lens is 40cm. The area of the image is nine times larger than that of the square. Select the correct statement(s):

The distance between the object and its real image from the convex lens is 60 cm and the height of image is two times the height of object . The focal length of the lens is

The distance between the object and its real image from the convex lens is 60 cm and the height of image is two times the height of object . The focal length of the lens is

When an object is placed at a distance of 15 cm from a convex lens, a real image is formed at a distance of 30 cm. What is the focal length of the lens?

An illuminated object is placed at a distance of 20 cm from a converging lens of focal length 15 cm. The image obtained on the screen is: