Question

I=2cm u=12cm o=0.5cm. What is the Focal length? and find u also​

Answer 1

Answer:

Focal length is 4 cm

Explanation:

h2 = 2 cm (Erect image)

v = - 12 cm (Erect image)

h1 = 0.5 cm

m = v/u = h2/h1

-12/u = 2/0.5

u = -3 cm

lens formula : 1/v – 1/u = 1/f

1/-12 – 1/-3 = 1/f

(-1 + 4)/12 = 1/f

F = 4 cm