A rod of length 10 cm lies along the principal axis of a concave mirror of focal length 10 cm in such a way that its end closer to the pole is 20 cm away from the mirror. The length of the image is :

Question

Dr. Abubacker · Accepted Answer

[Solution from source] The near end at 20 cm = 2f images at 20 cm. For the far end, u = −30 cm: 1/v = 1/f − 1/u = −1/10 + 1/30, so v = −15 cm. The image extends from 15 cm to 20 cm, a length of 5 cm. Answer (4).

Q. A rod of length 10 cm lies along the principal axis of a concave mirror of focal length 10 cm in such a way that its end closer to the pole is 20 cm away from the mirror. The length of the image is :

Explanation

Reviewed by Dr. Abubacker

Want to attempt the full paper?