Question

E X ERC I SE S
1. Which one of the following materials cannot be used to make a lens?
2. The image formed by a concave mirror is observed to be virtual, erect and
(b) Glass
(c)
Plastic
(a) Clay
than the object. Where should be the position of the object?
(a) Between the principal focus and the centre of curvature
(b) At the centre of curvature
(c) Beyond the centre of curvature
(d) Between the pole of the mirror and its principal focus.
3. Where should an object be placed in front of a convex lens to get a real image a
size of the object?
(a) At the principal focus of the lens
(b) At twice the focal length
At infinity
Between the optical centre of the lens and its principal focus.
herical mirmr and a thin spherical lens have each a focal length of -15
S​

Answer 1

Answer:

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