In order to determine the focal length of a concave mirror, a student obtained a sharp image of the grill of a window in the laboratory wall on a screen. His teacher suggested that to get better result for focal length, he should focus a distant tree instead of the window grill. In which direction should the mirror be moved for this purpose so as to get a sharp image of the tree on the screen?(1) behind the screen(2) away from the screen(3) towards the screen(4) very far away from the screen

In order to determine the focal length of a concave mirror, a student

1.	In order to determine the focal length of a concave mirror, a student obtained a sharp image of the grill of a window in the laboratory wall on a screen. His teacher suggested that to get better result for focal length, he should focus a distant tree instead of the window grill. In which direction should the mirror be moved for this purpose so as to get a sharp image of the tree on the screen?(1) behind the screen(2) away from the screen(3) towards the screen(4) very far away from the screen
Answer» In order to determine the focal length of a concave mirror, a student obtained a sharp image of the grill of a window in the laboratory wall on a screen. His teacher suggested that to get better result for focal length, he should focus a distant tree instead of the window grill. In which direction should the mirror be moved for this purpose so as to get a sharp image of the tree on the screen? (1) behind the screen (2) away from the screen (3) towards the screen (4) very far away from the screen