Rays from Sun converge at a point 15 cm in front of a concave mirror. Where should an object be placed so that size of its image is equal to the size of the object?
A. 30 cm in front of the mirror
B. 15 cm in front of the mirror
C. Between 15 cm and 30 cm in front of the mirror
D. More than 30 cm in front of the mirror
Dear Student,
As the light rays coming from the sun are converging at a point 15 cm in front of a concave mirror, so the focal length of concave mirror is 15 cm.
i.e. f = 15 cm
The concave mirror form image equal to the size of object, when the object is placed at a distance twice the focal length of the mirror.
Object distance = 2f = 2 × 15 => 30 cm
So, the object should be placed at a distance 30 cm in front of the mirror (option A)
Regards
As the light rays coming from the sun are converging at a point 15 cm in front of a concave mirror, so the focal length of concave mirror is 15 cm.
i.e. f = 15 cm
The concave mirror form image equal to the size of object, when the object is placed at a distance twice the focal length of the mirror.
Object distance = 2f = 2 × 15 => 30 cm
So, the object should be placed at a distance 30 cm in front of the mirror (option A)
Regards