1.5 Lenses Flashcards
What is the other name for a converging lens?
Convex lens
What does a convex lens look like?
Thin at the top and fat in the middle
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What does a diverging lens do?
Makes parallel rays spread out as if they came from the focal point
What is the other name for a diverging lens?
Concave lens
What does a diverging lens look like?
Wide at the top and thin in the middle
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What is the focal length?
The distance to the focal point from the centre of the lens
Why is there a focal point on either side of the lens?
Because light can pass through the lens in either direction
Name 6 ways to describe the image formed
- magnified or diminished
- inverted or upright
- real or virtual
What does the size of the image depend on?
How far the object is from the lens, the nearer the object to the lens, the larger the image
Calculation for the magnification produced by a lens?
Image height/object height
Give an example of a virtual image
Your reflection
What type of image is always formed through diverging lenses?
Virtual
What happens to the focal length when the curve of the converging lens increases?
The steeper the curve, the shorter the focal length
What is the principal focus of a converging lens?
The point where the parallel light rays are all converged to a point
How can a converging lens be made to produce a virtual image?
If the object is nearer to the lens than the principal focus
