7. If the diameter of the field of view when using the 4x objective is 3 mm, what is the area of the field of view when using the 4X, 10X, and 40X objectives

Using 4X view =

1.767 x 4 = 7.068mm

Using  10X view

1.767 x 10 = 17.67mm

Using 40X view

1.767 x 40 = 70.68mm.

Explanation:

If the diameter when using 4x objective = 3mm

then the original diameter = 3/4 = 0.75 mm

The diameter of the field is 0.75 mm

Area of a circle = pie/4 x diameter square

pie = 22/7 or 3.14

diameter = 0.75

The area of the field

3.14 x 0.75 2 =

3.14 x 0.5625=

1.767mm.

The original area of the field = 1.767mm

Using 4X view =

1.767 x 4 = 7.068mm

Using  10X view

1.767 x 10 = 17.67mm

Using 40X view

1.767 x 40 = 70.68mm.