magnification

Question 1

Describe how the size of an object viewed with an optical microscope can be
measured

Answer 1

-line up (scale of) eyepiece graticule with (scale of) stage micrometre

• Calibrate eyepiece graticule - use stage micrometre to calculate size of divisions on eyepiece graticule.
  *Measure the object: Count how many divisions it covers using the calibrated graticule.

Calculate actual size: Multiply the number of divisions by the length per division.

Recalibrate eyepiece graticule at different magnifications

Question 2

What does resolution mean

Answer 2

-the mininum distance between 2 objects in which they can be classed as seperate
-determined by wavelengths

Question 3

What does magnification mean

Answer 3

-how many times larger the image is compared to the object

Question 4

Calculate the size of divisions on 4 eyepiece graticule

Answer 4

● 4 eyepiece graticule divisions
= 10 stage micrometre divisions
● In this stage micrometre, 1 subdivision
= 10 μm
● So 4 eyepiece graticule divisions
= 10 μm x 10 = 100 μm
● So 1 eyepiece graticule division
= 100 μm/4 = 25 μm

Question 5

Whats an eyepiece graticule

Answer 5

the scale on the glass disc in the optical microscope

Question 6

Whats the stage micrometer

Answer 6

*used to calibrate eye puiece graticule
-each sub division in 10 micrometers apart.