wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

A concave lens of focal length 15cm forms an image 10cm from the lens. how far is the object placed from the lens?

Open in App
Solution

Given,

focal length, f = -15 cm

Distance of image, v = -10 cm

Distance of object, u =?

We know that,

1/v - 1/u = 1/f

So,

1/-10 - 1/u = 1/-15

So, -1/10 + 1/15 = 1/u

(-3 + 2)/30 = 1/u

-1/30 = 1/u

Therefore u = -30 cm

Thus object is placed 30 cm away from the concave lens.

Negative sign shows that object is at 30cm in front of the lens.



flag
Suggest Corrections
thumbs-up
5
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Image formation by concave lens
PHYSICS
Watch in App
Join BYJU'S Learning Program
CrossIcon