A diverging lens of focal length 30cm produces an image 2...
A diverging lens of focal length 30cm produces an image 20cm from the lens. Determine the object distance
10cm
12cm
50cm
60cm
Correct answer is B
Lens formula:
1f=1do+1di
where f, do and di are the focal length, object distance and image distance respectively.
The distance from the lens to the focal point is called the focal length. For converging lenses, the focal length is always positive, while diverging lenses always have negative focal lengths.
⇒ −130=1do+120
1do=−130−120
1do=−2+−360
→ \frac{-5}{60}\) = \frac{-1}{12}\)
do=−12cm
The object distance -12cm = 12cm on the other side of the lens.