Waves and Optics
Magnification
To calculate magnification and explain how image size compares with object size.
What you will learn
What magnification means
How to calculate magnification from image and object heights
How to rearrange the magnification equation
What a magnification greater or less than one means
Why magnification alone does not tell you image type
Explanation
Magnification is image height divided by object height. Use the same units for both heights; magnification has no unit. Values greater than 1 indicate a larger image, while values between 0 and 1 indicate a smaller image. This size ratio alone does not determine whether an image is real or virtual. Example: Image height is 30 mm and object height 10 mm. Calculate magnification. Magnification = image/object = 30/10 = 3, with no unit because the matching length units cancel. Link cause and effect.