Question

An object of height 3cm is placed in front of a convex lens of focal length 20 cm at a distance of 30 cm. Calculate image distance​

Answer 1

Explanation:

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12th

Physics

Ray Optics and Optical Instruments

Combination of Mirror and Lenses

An object 3 cm high is plac...

PHYSICS

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Asked on December 20, 2019 by

Arsh Malhotra

An object 3 cm high is placed 12 cm in front of a convex lens of focal length 8 cm find the nature and size of image formed.

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ANSWER

u=−12cm

f=+8cm

ho=+3cm

Using mirror formula,

v

1

+

u

1

=

f

1

v

1

+

−30

1

=

8

1

v

1

−

30

1

=

8

1

v

1

=

8

1

+

30

1

v

1

=

60

3+2

v

1

=

60

5

=

12

1

v=+12cm

Therefore, the image will be formed at a distance of 12cm behind the mirror.

m=

um

−v

=

−30m

−12

=+0.4

m=

h

o

h

i

0.4=

h

o

h

i

0.4=

1

h

i

h

i

=+0.4cm

Therefore, the image formed is diminished in size.