Turning Point

Question 1

Lens Focal Length F= -25 cm. Lens power is....
A. +4
B. +2
C. 0 
D. -2
E. -4

Answer 1

E. -4

Question 2

Object is located 50 mm in front of a lens. Object beam vergence is...
A. -50
B. -20
C. -10
D. -5

Answer 2

B. -20 D

Question 3

Object is located distance f in front of a plus lens of focal distance f. Object beam vergence is....
A. -P
B. 0
C. +P
D. infinity

Answer 3

A. -P

Question 4

Object is located at location xo = +120 cm after a lens. Object beam vergence is....
A. +1.2 D
B. +0.8333
C. -0.8333
D. -1.2

Answer 4

B. +0.833

Question 5

Object is located 10 cm after a lens. Object beam vergence is...
A. -10
B. -1
C. +1
D. +10

Answer 5

A. -10

Question 6

An image is 5x the size of an image. What type of lens is this?

Answer 6

Plus lens

Question 7

The image is half the size of the object.

Answer 7

Can be produced by positive or minus lens

Question 8

A negative lens forms only virtual images. Sure?
A. Yes
B. No
C. Only for real objects
D. Only for virtual objects

Answer 8

A. Yes

Question 9

A minus lens only produces ____ images.

Answer 9

smaller

Question 10

Convex mirror with focal length f = 20 cm has optical power P= -(1/f)

A. +5
B. 0
C. -5
D. -20

Answer 10

C. -5 D

Question 11

A concave mirror with optical power +20 D has focal length…
f= -(1/p)

A. -20 cm
B. -5 cm
C. 0 
D. +5 cm
E. +20 cm

Answer 11

B. -5 cm

Question 12

The Concave Mirror... (Select 3)
A. Collects Light
B. Converges object beam
C. Has Positive Optical Power
D. Has Positive Radius of Curvature

Answer 12

A. Collects Light
B. Converges object beam
C. Has Positive Optical Power

Question 13

What effect do we see in this picture?
A. Convex Mirror Imaging
B. Concave Mirror Imaging
C. Plus Lens Imaging
D. Minus Lens Imaging

Answer 13

D. Minus Lens Imaging

Question 14

The Optical Power of a thin lens is…
A. The Sum of the Optical Powers of each SSRI
B. The Difference of the Optical Powers of each SSRI
C. Twice the Optical Power of the first SSRI
D. Twice the Optical Power of the second SSRI

Answer 14

A. The sum of the optical powers of each SSRI

Question 15

The Optical Power of a thick lens, in comparison to the sum of the optical powers of the two SSRI's is....
A. Exactly equal
B. Larger
C. Smaller
D. Can be larger or smaller

Answer 15

D. Can be larger or smaller

Question 16

For ball lens of glass with n=1.5, the focal distance in air is..
A. f=1.0xR
B. f=1.5xR
C. f=2.0xR
D. f=2.5xR

f(ball lens) = (1/p) = (nR)/2(n-1)

Answer 16

B. f= 1.5xR

Question 17

The Hoegh Meniscus…(Material Glass, surrounded by Air)
A. Has positive optical power (plus lens)
B. Has negative optical power (minus lens)
C. Has either positive or negative optical power
D. Cannot tell from the formula provided

P=(d/n)* (n-1)2 / R2

Answer 17

A. Has positive optical power (Plus lens)

Question 18

The cornea, if it were surrounded by air would have an optical power...
A. -52 D
B. -5.2 D
C. +48 D
D. +4.8 D

Answer 18

B. -5.2 D

Question 19

The most important factor that the cornea is a strong plus lens is…
A. The value of the two radii of curvature
B. The value of its refracting index
C. The value of the cornea thickness
D. The fact that the posterior surface is surrounded by the aqueous, with nearly similar refractive index.

Answer 19

D. The fact that the posterior surface is surrounded by the aqueous, with nearly similar refractive index.