Magnification And Power Flashcards
What do magnifying glasses do?
Create a magnified virtual image
How does a magnifying glass work?
Object being magnified must be closer to the lens than the focal length
The image produced is virtual
How do you work out magnification?
Magnification= image height / object height
What is focal length related to?
The power of the lens
More powerful the lens, shorter the focal length
How do you work out the power of the lens?
Power = 1/focal length (m)
What is the power for converging and diverging lenses?
Converging = positive Diverging = negative
What two factors determine the focal length?
The refractive index of the lens material
The curvature of the two surfaces on the lens
What happens for a given focal length?
The greater the refractive index of the material used to make the lens the flatter the lens will be
What is the focal length?
From centre of lens to focal point
