Basic of Microscope Part 1

Which part of the compound microscope helps in gathering and focusing light rays on the specimen to be viewed?

• a)Eyepiece lens
  

• 
  b) Objective lens
  

• c) Condenser lens
  

• d) Magnifying lens

Answer explanation

Compound microscope contains three separate lens systems. The condenser lens is placed between the light source and the specimen and it gathers and focuses the light rays in the plane of the microscopic field to view the specimen.

What is the minimum distance for the eye to focus any object is​ (a)  

• 25
• 11
• 32
• 20

Answer explanation

The eye cannot focus on objects brought closer to it less than 25 cm; this is, accordingly the distance of maximal effective magnification. An object must also subtend an angle at the eye of 1 degree or greater.

Match the following

• regulates the amount of light that reaches the specimen

• 
• Moves the stage slightly to SHARPEN the image

• 
• Total magnification

• 
• Moves the stage up and down for FOCUSING

• 

Which part of the light microscope controls the intensity of light entering the viewing area? ​ (a)  

• Condenser
• Coarse adjustment screw
• Fine adjustment screw
• Diaphragm

Answer explanation

On the condenser is mounted a shutter like an apparatus called the diaphragm which opens and closes to permit more or less light into the viewing area. Condenser lens just helps in condensing the light rays. Coarse and fine adjustment screws are used for focusing under different power lens.

Label the parts 1,2,8,9, of the Microscope

d

c

b

a

LIGHT SOURCE

Revolving turret

Body tube

Ocular lens