What is the distance of an object from a convex lens to form an magnified asbestos image of an object? Same of f/ same of 2f / less than f/ greater than f
Answers
Explanation:
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12th
Physics
Ray Optics and Optical Instruments
Combination of Mirror and Lenses
A concave lens forms the im...
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Asked on December 26, 2019 by
Priyanshi Tirkey
A concave lens forms the image of an object such that the distance between the object and image is 10 cm and the magnification produced is 1/4. The focal length of the lens will be
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ANSWER
The correct option is D.
Given,
The distance between the object and mirror =10 cm and magnification is
4
1
Magnification is the ratio of the height of the image with the height of the object
=
u
v
u−v=10cm
v=u−10cm
⇒
u
v
=
u
u−10
=
4
1
⇒4u−40=u
u=
3
40
cm
v=
3
10
cm
Now,
By Lens formula:
f
1
=
v
1
−
u
1
f
1
=
10
3
−
40
3
f
1
=
40
9
f=
9
40
cm
Focal length, f=4.4cm