In an experiment to determine the focal length of a convex lens, a sharp inverted image of a distant light house is obtained on a screen behind the lens. Then the screen is removed and if one looks through the lens in the direction of the light house, he/she will observe: (see options below)

Question

In an experiment to determine the focal length of a convex lens, a sharp inverted image of a distant light house is obtained on a screen behind the lens.  Then the screen is removed and    if one looks through the lens in the direction of the light house, he/she will observe: (see options below)

anonymous · Answer

a) no image as the screen has been removed.
b) an erect image of the light house on the lens.
c) an inverted image of the light house at the focus of the lens.
d) a blurred image of the light house on the wall of the laboratory.

anonymous · Answer

I am sure a) and d) are not the right answers and hence can be ruled out.....

I think it should be b) but am not sure...

Anybody with suggestion as to what is the right answer??

mani_jha · Answer

It depends on where you are standing. If you are standing within the focal length of the lens, b is correct. Otherwise, c is correct

anonymous · Answer

Thanks for the answer Mani but r u 100% sure abut this answer???

mani_jha · Answer

No, not 100% sure. Actually, I havent started optics yet, but I have done experiments on it in school

anonymous · Answer

checked from some other source....
it is    c) an inverted image of the light house at the focus of the lens.