Question

A concave mirror of focal length 15 cm forms an image having twice the linear dimensions of the object. The position of the object when the image is virtual will be-

• A. 22.5 cm
• B. 7.5 cm
• C. 30 cm
• D. 45 cm

Answer 1

Answer: (B)

7.5 cm

Answer 2

F =– 15cm for virtual & 2 times large image m = + 2

m = $\frac { - 15 } { - 15 - u }$

– 30 – 2u = – 15

– 2u = 15

u = – 7.5 cm