Question

a lens of focal length 40 cm forms of four times real and magnified image at what position will the image be formed?​

Answer 1

Answer:

magnification given is 4 times

it means (height of image/height of object) =(-v/u) =4

u=(-v) /4

now using the mirror formula

also here f=(-40) (focal length of concave mirror is negative)

1/f=1/v +1/u

1/(-40)=1/v + (-4)/v

1/(-40)= (-3)/v

v=3*40=120

u= (-120/4)=(-30)

u= (-30)cm

hence object should be 30 cm away from the pole

Explanation:

Answer 2

Answer:

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