Microscope Simple and Compound - UNSOLVED PRACTICE SET
Chapter: Ray Optics and Optical Instruments | Topic: Microscope Simple and Compound
MICROSCOPE SIMPLE AND COMPOUND - UNSOLVED PRACTICE SET
Topic: Microscope Simple and Compound
Multiple Choice Questions
Q1. The magnifying power of a simple microscope is:
- M = D/f
- M = 1 + D/f
- M = f/D
- M = D × f
Q2. For a compound microscope, the final image is:
- Real and inverted
- Virtual and erect
- Virtual and inverted
- Real and erect
Q3. In a compound microscope, the objective lens forms:
- A virtual, erect, magnified image
- A real, inverted, magnified image
- A real, erect, diminished image
- A virtual, inverted, diminished image
Q4. The magnifying power of a compound microscope when the final image is formed at infinity is:
- M = (L/f₀) × (D/fₑ)
- M = (L/f₀) × (1 + D/fₑ)
- M = (f₀/L) × (D/fₑ)
- M = (L/f₀) + (D/fₑ)
Q5. The resolving power of a microscope can be increased by:
- Decreasing the wavelength of light used
- Increasing the wavelength of light used
- Using a lens with smaller apertureC
- Decreasing the refractive index of the medium
Q6. In a compound microscope, the distance between the objective and eyepiece is:
- Less than f₀ + fₑ
- Greater than f₀ + fₑ
- Equal to f₀ + fₑC
- Zero
Short Answer Questions
Q7. Define magnifying power of a simple microscope. Write the expression when the image is formed at the near point.
Q8. Why does a compound microscope have greater magnifying power than a simple microscope?
Q9. In a compound microscope, why is the focal length of the objective much smaller than that of the eyepiece?
Q10. What is the resolving power of a microscope? On what factors does it depend?
Q11. Why is oil immersion used in high-power microscopes? Explain briefly.
Q12. A simple microscope has a focal length of 5 cm. Calculate its magnifying power when the image is formed at the near point (D = 25 cm).
Long Answer Questions
Q13. With the help of a ray diagram, explain the working of a simple microscope. Derive the expression for its magnifying power when the image is formed at the near point.
Q14. Describe the construction and working of a compound microscope with a neat ray diagram. Derive the expression for its magnifying power when the final image is formed at infinity.
Q15. Explain the concept of resolving power of a microscope. State the expression for the limit of resolution and discuss how it can be improved.
Numerical & Application-Based Problems
Q16. A compound microscope has an objective of focal length 1.0 cm and an eyepiece of focal length 5.0 cm. The distance between them is 20 cm.
(a) Calculate the magnifying power when the final image is formed at the near point (25 cm).
(b) Calculate the magnifying power when the final image is formed at infinity.
(c) Determine the position of the object for the eyepiece when the final image is at the near point.
Q17. A simple microscope has a convex lens of focal length 10 cm.
(a) Calculate the magnifying power when the image is formed at the near point (25 cm).
(b) Calculate the magnifying power when the image is formed at infinity.
(c) An object of size 1 mm is viewed through this microscope with the image at the near point. Calculate the size of the image seen by the eye.
Q18. In your school's biology lab, students use a compound microscope to observe onion peel cells.
(a) The microscope has an objective of focal length 4 mm and an eyepiece of focal length 2.5 cm. The distance between them is 20 cm. Calculate the magnifying power when the final image is formed at 25 cm.
(b) The students observe that they can see cells clearly at one magnification but not at higher magnification. Explain why increasing magnification beyond a certain point does not improve the view.
(c) A student suggests using blue light instead of white light to see finer details. Explain whether this would help and why.
(d) In India, many diagnostic labs use microscopes to detect malaria parasites in blood samples. Explain why high magnification and good resolution are both essential for this purpose, and how the microscope design achieves this.