# General Principles of optics Question

## Important Question

1. The instrument used to view microorganisms is known as a:

• a) Telescope
• b) Kaleidoscope
• c) Microscope
• d) Bioscope

2. The lens system nearer to specimen is known as:

• a) Boy tube
• b) Objective
• c) Eye-piece
• d) Mirror

3. What is correct for body tube?

• a) A tube through which we handle microscope
• b) A tube consists of 2 sets of lenses
• c) A tube consists of condenser lenses
• d) All of the above

4. further magnifies the image formed by the _:

• a) Eye-piece, objective
• b) Objective, eye-piece
• c) Eye-piece, condenser
• d) Condenser, objective

5. What is projection distance?

• a) The distance between microscope base and eye-piece
• b) The distance between body tube and mirror
• c) The distance between virtual image and eye-point
• d) The distance between virtual image and objective

6. Which lens will magnify the object first?

• a) Mirror
• b) Condenser
• c) Ocular
• d) Objective

7. What is the tube length of microscope generally adopted by most microscope manufacturers?

• a) 160 mm
• b) 160 cm
• c) 250 mm
• d) 250 cm

8. What is the project distance mostly found in bright field microscope?

• a) 160 mm
• b) 160 cm
• c) 250 mm
• d) 250 cm

9. The total magnification of the microscope is equal to the:

• a) Magnifying power of the objective lens multiplied by magnifying power of the ocular
• b) Sum of the magnifying power of the ocular and objective lens
• c) Magnifying power of the objective lens multiplied by magnifying power of the condenser
• d) None of the above

10. The image of specimen produced by objective lens is usually:

• a) Real and upright
• b) Real and inverted
• c) Virtual
• d) All of the above

11. The total magnification of microscope becomes equal to the magnifying power of objective
lens multiplied by the magnifying power of the ocular, when glass slide is placed ________from
the ocular of microscope.

• a) 20 inches
• b) 10 cm
• c) 10 inches
• d) 20 cm

12. If the distance between ground glass and eyepiece is 5 inches instead of 10 inches, the
magnification will become:

• a) Double
• b) As it is
• c) One half
• d) None of the above

13. The magnification of objective lens is 50 X, magnification of ocular is 5 X, and distance of
ground glass from ocular is 6 inches. What will be the total magnification?

• a) 250
• b) 150
• c) 300
• d) 500

14. The magnification of objective lens is 95 X, magnification of ocular is 10 X, and distance of
ground glass from ocular is 9 inches. What will be the total magnification?

• a) 950
• b) 855
• c) 955
• d) 850

15. When a light ray pass to one medium to another:

• a) It bents at interface
• b) It remains straight
• c) It will get splitted
• d) All of the above

16. When a light ray pass from one medium to another, it bents at interface. This phenomenon is called:

• a) Reflection
• b) Refraction
• c) Transmission
• d) Resolution

17. Refractive index is:

• a) A result of refraction.
• b) A measure of how greatly a substance slows the light velocity.
• c) Used to determine the direction &magnitude of bending.
• d) All of the above

18. Refractive index of glass is:

• a) Higher than air
• b) Lower than air
• c) Equal to air
• d) One half in comparison with air

19. Lenses act like collection of _______ operating as a unit.

• a) Surfaces
• b) Slides
• c) Prisms
• d) All of the above

20. A convex lens focuses light rays at a specific point called:

• a) Light point
• b) Focal length
• c) Focal place
• d) Focal point

21. The distance between center of the lens & focal point is known as:

• a) Focal length
• b) Wavelength
• c) Both of the above
• d) None of the above

22. Human eyes cannot focus on objects nearer than about:

• a) 65cm
• b) 25cm
• c) 35cm
• d) 45cm

23. Magnification of lens increases as focal length:

• a) Increases
• b) Increases or decreases
• c) Decreases
• d) None of the above

24. Compound microscopes are made up of what?

• a) Objective lens
• b) Eye piece
• c) Objective lens with additional lenses
• d) Only one lens