SME
Grade 6 Science · Problem type
Total magnification
Use this for “A 10× eyepiece and a 40× lens: what is the total magnification?”
Table
Objective power
(×)
Total magnification
(×)
This is an example. Type your own values to start a new problem.
e
×
o
=
t
Formulas
10 × 40 = 400
Eyepiece power × objective power = total magnification
Assumptions
•
The eyepiece is the lens you look through: 5×, 10×, 15× or 20×. Most school microscopes use 10×.
•
The objective is the lens near the slide: 4×, 10× or 40×; some microscopes also have 100×.
•
400× means the image looks 400 times as wide as the real thing.
•
At higher power fewer cells fit in the circle, but each looks bigger.
Step-by-step
WE KNOW
Eyepiece power: 10×
Objective power: 40×
FIND
total magnification
Step 1 · Find total magnification
10 × 40 = ?
Eyepiece power × objective power = total magnification
Each lens enlarges the image the other one makes, so multiply the two powers.
Total magnification = 400×
Check
Put the numbers back in. Both sides should match.
10 × 40 = 400 ✓
Topic check
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