2.3 Lenses

Question 1

Lens equation

Answer 1

1/u+1/v=1/f

Question 2

Power equation

Answer 2

P=1/f

Question 3

Magnification equation

Answer 3

M=v/u

Question 4

Object, image, focal points and focal lengths differences when real, virtual, converging and diverging

Answer 4

Real->+
Virtual->-
Converging->+
Diverging->-

Question 5

Converging and diverging power

Answer 5

Converging power = +
Diverging power = -

Question 6

Linear magnification definition

Answer 6

The size of the image divided by the size of the object

Question 7

Focal length definition

Answer 7

The distance from the centre of the lens to the focal point

Question 8

Principle focus definition

Answer 8

The point where all rays converge

Question 9

Short sighted causes (myopia)

Answer 9

1. Lens is too strong
2. Eye is too long

Question 10

Long sighted causes (hypermetropia)

Answer 10

1. Lens is too weak
2. Eye is too short