[physics] thin converging lens

Question 1

what is the principal axis

Answer 1

the line which passes through the centre of the lens and is perpendicular to the plane of the lens

Question 2

principal focus/principal focal point

Answer 2

the point on the principal axis where all the rays parallel to the principal axis meet after passing through the lens

Question 3

symbol for principal focus

Answer 3

F

Question 4

focal length

Answer 4

distance between optical centre and the principal focal point

Question 5

symbol for focal point

Answer 5

F

Question 6

optical centre

Answer 6

point of the principal axis that is the midpoint between the surface of the lens

Question 7

symbol for optical centre

Answer 7

C

Question 8

focal plane

Answer 8

plane perpendicular to the principal axis on which all parallel rays meet after passing through the lens

Question 9

special thing to note about

Answer 9

when the parallel beam of rays incident on a thin converging lens is not parallel to the principal axis, the rays are reflected to a point P on the focal plane

Question 10

u=infinity

Answer 10

• inverted
• real
• diminished
• opposite

Question 11

uses of u=infinity

Answer 11

telescope

Question 12

u>2f

Answer 12

• inverted
• real
• diminished
• opposite

Question 13

uses of u>2f

Answer 13

camera/eye

Question 14

u=2f

Answer 14

• inverted
• real
• same size
• opposite

Question 15

uses of u=2f

Answer 15

photocopier

Question 16

f<u<2f

Answer 16

• inverted
• real
• magnified
• opposite

Question 17

uses of f<u<2f

Answer 17

projector

Question 18

u=f

Answer 18

• upright
• real
• magnified
• same side

Question 19

uses of u=f

Answer 19

spot light

Question 20

u<f

Answer 20

• upright
• real
• magnified
• same side

Question 21

uses of u<f

Answer 21

magnifying glass

Question 22

draw out all the graphs

Answer 22

refer to notes