Magnification and Resolution

Question 1

What is magnification?

Answer 1

The number of times larger an image is than the actual object

Question 2

What is the formula for magnification?

Answer 2

magnification= size of image / size of real object

can be rearranged - using the I AM equation triangle:
i = image/drawing size
a = actual size of image
m = magnification

MAGNIFICATION HAS NO UNITS

Question 3

How does magnification vary?

Answer 3

The ability of a microscope to magnify an object depends on the type of microscope, and on the features of the microscope itself.

Question 4

What is resolution?

Answer 4

The ability to distinguish separate points on an image as two separate objects

Question 5

How does resolution vary in microscopes?

Answer 5

light microscopes - resolution is limited by the wavelength of light
electron microscopes - resolution is much higher because electrons have a smaller wavelength than visible light

Question 6

What are the features of a light microscope?

Answer 6

• max resolution of 20nm
• max useful magnification of around x1500-2000
• can be used to view dead or living organisms
• useful for looking at whole cells, small organisms and tissues within organs, such as in leaves or skin

Question 7

What are the features of an electron microscope?

Answer 7

• max resolution of 0.5nm (TEMs) or 3-10 nm (SEM)
• capable of generating images of a magnification of more than x500 000
• TEMs are capable of a higher magnification than SEMs due to their higher resolution
• can only be used for viewing dead specimens
• useful for looking at organelles or viruses, as well as looking at whole cells in detail