Question

1P
6. A 5cm high object is placed at a
distance of 30cm in front of a convex
lens having a focal length 15cm.
height of image will be:
O 15cm
O 30cm
O 5cm
O 10cm​

Answer 1

Answer:

Height of object, h

o

=5cm, object distance u=−30cm, focal length f=−20cm

Now, from mirror formula :

f

1

=

v

1

+

u

1

v

1

=

f

1

−

u

1

=

20

−1

+

30

1

=−

60

1

v=−60cm - image distance

Magnification, m=−

u

v

=−

−30

−60

=−2

Size of image, h

i

=m(h

o

)=−2(5)=−10 cm