Optical power

Question 1

What does optical power refer to?

Answer 1

The amount that a lens, mirror, or other optical system, either converges or diverges light

Question 2

P=

Answer 2

Power in Dioptres (D)

Question 3

F =

Answer 3

Distance from the point of focus in meters (m)

Question 4

U= 1/u

Answer 4

Distance of the object from the lens (m)

Question 5

V= 1/v

Answer 5

Distance of the image from the lens (m)

Question 6

Negative values indicate

Answer 6

Placement in front of the lens

Question 7

Positive value indicates

Answer 7

Placement behind the lens

Question 8

Calculate the power of a lens with the focal length of 2 m

Answer 8

P = 1/f
P = 1/2
P= 0.5 D

Question 9

Calculate the power of a lens with the focal length of five cm

Answer 9

P = 1/f
P = 1/ 0.05cm
= 20

Question 10

Calculate the focal length of a 10 D lens

Answer 10

F = 1/p
F = 1/10
= 0.1 m

Question 11

Calculate the focal length in cm of a 25 D lense

Answer 11

F = 1/p
F = 1/25
= 0.04
= 4cm

Question 12

An object is located 1m in front of a -3 D lens. Where is the image?

Answer 12

V= U + D
= 1/-1 + -3
= -4
V= 1/-4
= -0.25m