Home › Andhra Pradesh SSC (Class 10) › Physics › Reflection of Light at Curved Surfaces › An object is placed 25 cm in front of a concave …
An object is placed 25 cm in front of a concave mirror of focal length 15 cm. The image distance v is
A-9.4 cm
B+37.5 cm
C-18.75 cm
D-37.5 cm
Answer & Solution
Correct answer: D. -37.5 cm
1. Sign convention: f = -15 cm, u = -25 cm.
2. 1/v = 1/f - 1/u = (1/-15) - (1/-25).
3. 1/v = -1/15 + 1/25 = (-5+3)/75 = -2/75.
4. So v = -37.5 cm, a real image in front of the mirror.
_Source: AP/TS SCERT Class 10 Physical Science, "Reflection of Light at Curved Surfaces"_
Related questions
A concave mirror forms an erect image only when the object is placedA convex mirror gives a wider field of view than a plane mirror of the same size because iFor a concave mirror, when the object is placed at the centre of curvature, the magnificatA real image formed by a mirror is one thatFor a concave mirror, when the object is placed exactly at the focus, the image is formedThe focus of a convex mirror isThe normal at any point on a spherical mirror lies along the line joining that point to thA spherical mirror has a radius of curvature of 30 cm. Its focal length is