Question

9.Rohit focused the image of a candle flame on a white screen using

a convex lens.He noted down the position of the candle,screen

and lens as under

Position of candle=26cm

Position of convexlens=50cm

Position of screen=74cm

(a)What is the focal length of convex lens?

(b)Where will the image be formed if he shifts the candle towards

the lens at a position of 38cm?​

Answer 1

Answer:

).Distance of object from lensu=50−26=24cm

Distance of the screen from the lensv=74−50=24

From lens formula,

v

1

−

u

1

=

f

1

24

1

−

−24

1

=

f

1

2

24

=−f

f=−12cm

(B). Now when the object is shifted to distance of 38 cm u=50−38=12cm

Since u=f, the image will form at infinity.

solution

hope it helps u

Answer 2

Answer:

.Rohit focused the image of a candle flame on a white screen using

a convex lens.He noted down the position of the candle,screen

and lens as under

Position of candle=26cm

Position of convexlens=50cm

Position of screen=74cm

(a)What is the focal length of convex lens?

(b)Where will the image be formed if he shifts the candle towards

the lens at a position of 38cm?