Lenses + Ray Diagrams

Question 1

Principal axis

Answer 1

The path of light that goes straight through the middle

Question 2

Focal length

Answer 2

The distance from the lens to the principal focus

Question 3

Principal focus

Answer 3

Where the lines meet in convex

In concave where they meet where you continue with dotted lines behind the lens

Question 4

Ray diagram convex

Answer 4

Draw two axis, arrows at top/bottom of y axis
Draw an arrow to the top of the object
Draw from the top through the intercept
Draw one parallel along from the top and refract through the principal focus until they meet
Dotted lines back to where they would meet if <1F

Question 5

Ray diagram concave.

Answer 5

Same axis y like \/
                                 |
                                /\
Draw an arrow to the top of the object
Draw the line through the intercept 
Draw a parallel line from the top of the object 
Draw a dotted line from F on the side of the light to the line from the top of the object and continue on as a full line
Where they cross is the image

Question 6

> 2f convex

Answer 6

Real, inverted, diminished

Question 7

1-2F convex

Answer 7

Real, inverted, enlarged

Question 8

<1f convex (magnifying glass)

Answer 8

Upright, enlarged, virtual

Question 9

Concave results

Answer 9

Upright, diminished, virtual

Question 10

Lens shape

Answer 10

Convex bulges in, concave is thinner in