When an object is kept at a distance 20 cm in front of a concave mirror, a real image is formed at the centre of curvature of the mirroe. Magnification produced by the mirroe is ______________ .
-1
The correct answer is Option 3 i.e. -1.
Explanation:
Given:
Object distance (u) = –20 cm (negative as it's in front of the mirror)
Image is formed at the centre of curvature, so Image distance (v) = –20 cm (Real image formed on the same side as the object, so it’s negative)
Magnification (M) for a mirror is given by:
M=v/u
Substitute the values:
M=−20/−20 = +1
But for a real image formed by a concave mirror, the image is inverted, so the magnification is negative:
M =−1
Other options explained:
–20: would imply the image is 20 times larger, which isn’t the case here.
–10: not matching the actual image and object distances.
–0.5: would mean the image is smaller than the object.
When an object is kept in front of a concave mirror of a focal length of 10 cm, a real image is formed at a distance of 20 cm in front of the mirror. Here, the object distance is .............
The number of images observable between two parallel mirror is
Which of the following pair is correct?
I. Mirror formula : (1/v) – (1/u) = (1/f)
II. Lens formula : (1/v) + (1/u) = (1/f)
A ray of light is made incident on a concave mirror, parallel to its principal axis. After reflection it will -