Question

if an object of 7 cm heght is placed at a distance of 12 cm from a convex lens of focal length 8 cm foind the position,nature and height of image​

Answer 1

Answer:

Prabir Ghosh (born 1 March 1945) is the founder and president of Bharatiya Bigyan O Yuktibadi Samiti, a science and rationalists' association based in Kolkata, India. He is the author of a number of books in Bengali disputing supernatural claims and is well known for his book series titled Aloukik Noy, Loukik.

Explanation:

Answer 2

Given:-

• Height of object ,ho = 7cm

• Object distance u = -12cm

• Focal length,f = +8cm

To Find:-

• The position,nature and height of image

Solution:-

By using lens Formula

• 1/v - 1/u = 1/f

Substitute the value we get

→ 1/v = 1/f +1/u

→ 1/v = 1/8 + 1/(-12)

→ 1/v = 1/8 -1/12

→ 1/v = 3-2/24

→ 1/v = 1/24

→ v = 24 cm

The image distance is 24 cm .The image formed is real , inverted and larger than the object.

Now Calculating the Magnification

• magnification ,m = v/u = hi/ho

Substitute the value we get

→ m = -24/12 = hi/7

→ hi = -24×7/12

→ hi = -2×7

→ hi = -14 cm

Therefore, the image height is 14 cm .