Question

an object of hight 5cm is placed near infront of a convex lens of focal length 20cm .and image of hight 20cm is formed behind the mirror find v ?​

Answer 1

Answer:

u= -30 cm

f= -20 cm

By using mirror formula,

1/v + 1/u = 1/f

1/v + 1/-30 = 1/-20

v= -60 cm

negative sign indicates that image is in front of the mirror

Therefore,

The distance between image and object = 60–30 = 30cm

Answer 2

"" ❤️ Answer ❤️ ""

Given, u=-20cm

f

=10cm

v

=?

We know

f

1

=

v

1

−

u

1

10

1

=

v

1

−

20

(−1)

v

1

=

20

2−1

=

v= 20cm

h

o

h

i

=

u

−v

−20

20

=

−1=

h

o

h

i

h

0

5cm

h

i

=

−5cm

=