Starter Questions
1.
What is a real image?
Image on other side of lens from object.
2.
What is a virtual image?
Image on same side as object – cannot be seen on a screen
3.
Name 2 methods to find the focal length? u-v Method
Distance object
4.
List 4 possible errors that could occur in using the u-v Method?
Image is not sharp
Parallax error when using metre stick
Measurements not taken from centre of lens
Screen and lens are not vertical
5.
Why is an approximate value for focal length of lens found?
To determine where to position lens so that a real image can be seen on screen
6.
Why is there a larger error in v compared to u?
Difficult to know exactly where the sharp image is
7.
Give 2 uses of a converging lens?
Magnifying glass, cameras, microscopes, glasses for a near sided person.
8.
A converging lens is used as a magnifying glass. Draw a ray diagram to show how an erect image is formed by a magnifying glass.
9.
Magnification is equal to what formula? v/u or height2/height1
10.
A converging lens has a focal length of 8cm. Determine the 2 positions that an object can be placed to produce an image that is four times the size of the object