In an experiment to determine the focal length `(f)` of a concave mirror by the `u-v` method, a student places the object pin A on the principal axis at a distance x from the pole P. The student looks at the pin and its inverted image from a distance keeping his/her eye in line with PA. When the student shifts his/her eye towards left, the image appears to the right of the object pin. Then,

Options

A. `xltf`
B. `fltxlt2f`
C. x =2f
D. `xgt2f`

Answer

B

Explanation

First of all keep in mind that image and object both are on the same side . Invertecil image means real image. When observer shifts his/her eye towards left them image appears to the right of objected . If you have done experiments on optics then you can easily understand that given situation is possible only when image is nearer to observer and hence farther away from mirror than object . So we can understand that image distance is more than object , distance hence for real image it is possible only when object is kept between focus and centre of curvature of mirror . Or we can say that ` f lt x lt 2 f`.