Question

an equi convex lens whose focal length is air is 20cm is made up of material whose refraction index is 1.5. if one of its surface is shivered and then dipped in to a transparent liquid whose refractive index is 1.6.in the liq it behave like a which Lena​

Answer 1

Step-by-step explanation:

Given an equi convex lens whose focal length is air is 20cm is made up of material whose refraction index is 1.5. if one of its surface is silvered  and then dipped in to a transparent liquid whose refractive index is 1.6.in the liq it behave like a which Lens

• Given focal length of an equiconvex lens is 20 cm.
• One of the curved surface is silvered.
• Now 1/fm equivalent = 1/fm – 2/f l ------------ 1
• 1/ f length = μ (refractive index -1 ) (1/R1 – 1/R2)  
•            1/20  = 1.5 – 1 (1/R – 1 / - R)
•           2/R = 1/0.5 x 20
•          So R = 20 cm
• Focal length of the mirror = R / 2 = - R / 2
•                                                           = - 20 / 2
•                                                         = - 10 cm
• From equation 1 we get
•                       1/f m equivalent = 1/fm – 2 / fl
•                                                  = 1/- 10 – 2/20 (positive since it is a convex lens)
•                                                   = - 4/20  
•                                                  = - 1/5
•                        So fm equivalent = - 5 cm
•         Now there is a point centre of curvature.
• This centre of curvature will be two times fm which will be 10 cm

Reference link will  be

https://brainly.in/question/3043142