The crystalline lens of the human eye is a double-convex lens made of material h

Question

The crystalline lens of the human eye is a double-convex lens made of material having an index of refraction of 1.44 (although this varies). Its focal length in air is about 8.00 mm , which also varies. We shall assume that the radii of curvature of its two surfaces have the same magnitude.

(Note: The results obtained in the parts A, B and C are not strictly accurate, because the lens is embedded in fluids having refractive indexes different from that of air.)

Part A: Find the radii of curvature of this lens.

Part B: If an object 13.0 cm tall is placed 31.0 cm from the eye lens, where would the lens focus it?

Part C: How tall would the image be?

Part D: Is this image real or virtual?

Part E: Is it erect or inverted?

Explanation / Answer

n = 1.44

Let, R1 = R2 = R = ?

A) Use Len's makers formula,

1/f = (n-1)*(1/R1 + 1/R2)

1/f = (n-1)*(1/R + 1/R)

1/f = (n-1)*2/R

R = 2*(n-1)*f

= 2*(1.44-1)*8

= 7.04 mm or 0.704 cm

B) object distance, u = 31 cm

let v is the image distance.

Apply, 1/u + 1/v = 1/f

1/v = 1/f - 1/u

1/v = 1/0.704 - 1/31

v = 0.72 cm

C) magnification, m = -v/u

= -0.72/31

= -0.023

image hight = m*object height

= 0.023*13 cm

= 0.302 cm

d) image is real

e) inverted

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.