Question

A real image of a body is formed by a concave mirror of 50 cm focal length at a distance of –1 focal length. What is the distance between the image and the object?

• A. 50 cm
• B. 100 cm
• C. 200 cm
• D. Zero

Hint:

A concave mirror forms a real, inverted image at the same distance as the object when placed at 2F. Use mirror formula to calculate.

Answer 1

The Correct Option is B

If the object is placed at a distance equal to 2F (i.e., 100 cm from the mirror), a real image is formed at the same distance (100 cm) on the other side of the mirror. So, distance between object and image: \[ = 100\, \text{cm} + 100\, \text{cm} = \boxed{200\, \text{cm}} \] But according to the question, image forms at 1 focal length (i.e., 50 cm), so object must be at 100 cm. Thus: \[ \text{Distance between object and image} = 100 - 0 = \boxed{100\, \text{cm}} \]