(a) A ray of light after reflection from a concave mirror becomes parallel to its principal axis. Draw a…
(a) A ray of light after reflection from a concave mirror becomes parallel to its principal axis. Draw a labelled ray diagram to show this.
(b) (i) Differentiate between the virtual images formed by a convex mirror and concave mirror.
(ii) "The value of magnification 'm' for a mirror is –2." Calculate the height of object if the height of image is 20 cm.
Solution
(a)
(b)
(i)
Virtual Image formed by Virtual Image formed by
Convex mirror Concave mirror
Image is formed for all Image is formed when object
positions of the object is placed between Pole and
Principal Focus
Small/diminished Enlarged/magnified
(Any one difference)
(ii) 𝑚 = −2
[
height of image ℎ′
𝑚 = height of object = ℎ
ℎ′
ℎ=𝑚
−20
ℎ = −2
ℎ = 10 cm
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