Lenses Flashcards
1
Q
what is the difference between a converging lens and a diverging lens?
A
a converging lens is flatter in the middle whereas a diverging lens is thinner In the middle.
2
Q
what are converging lenses used for
A
to form images in telescopes cameras, projectors, binoculars and our eyes
3
Q
what is the focal length
A
the distance between the centre of the lens and the focal point
4
Q
the fatter the lens is the focal length shorter on longer
A
shorter
5
Q
how do you find a focal length of the converging lens?
A
you obtain an image of a distant object (eg tree or building) on a screen and measure the distance between the lens and the focused image
6
Q
what are lenses usually made of?
A
glass or plastic
