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

Question

A screen is placed at a distance 40 c m away from an illuminated object. A converging lens is placed between the source and the screen and an attempt is made to form the image of the source on the screen. If no position of the lens could be found, the focal length of the lens, must be less than 10 c m, must be greater than 10 c m, must not be greater than 20 c m, must not be less than 10 c m

MARKS App · Accepted Answer

Distance between object and image or screen is d = 40 c m If a converging lens makes real image of a real object then d ≥ 4 f f ≤ d 4 f ≤ 40 4 f ≤ 10 c m This is a condition for obtaining an image. As no image is found therefore focal length must be greater than 10 c m .

Search any question & find its solution

Looking for more such questions to practice?