Question

2) A needle 5cm high is placed at the distance of 20cm from convex lens of focal length 40cm. 2
Where is image formed?
b. What is the height of image?
Chemistr​

Answer 1

Answer:

Mirror formula is (1/v) + (1/u) = 1/f1/v = (1/f) − (1/u) = (−1/15) + (1/20) = −1/60 v = − 60 cm. The screen should be placed at 60 cm from the mirror. The image is real. Magnification m = h'/h = − v/u = 60/(– 20) = – 3 Height of the image h' = mh = (– 3)x5 = − 15 cm The image in inverted and enlarged.01-Oct-2017