A microscope with an objective lens lens of focal length 8.0 mm and an eyepiece

Question

A microscope with an objective lens lens of focal length 8.0 mm and an eyepiece of focal length 9.50 mm is used to view a red blood cell. An image of the cell is formed 160 mm beyond the objective (typical image distance for the objective of a biological microscope -- this is also known as the tube length L). If a microscope objective is labeled as 20x, this means it has a magnification of m0 = -s'/s = 20. What is the "non-standard" magnification of the above objective? The microscope is designed to place the image of the objective near the focal point of the eyepiece. What is the magnification of the eyepiece? What is the size of the image, if the blood cell is approximately 8 microns (10-6 m) in size? Two lenses, of focal lengths 3.0 cm and 30.0 cm, are used to build a small telescope. Which lens should be the objective? Why? Describe an image formed by the telescope. How far apart are the two lenses in the telescope? Why are the lenses arranged in this manner?

Explanation / Answer

L = f0+fe   = 8+9.5 = 17.5 mm

a. Mo = v/u = 160/8 = 20

b. Me = 160/9.5 =16.82

c. image size = M* object hright = 20 *8 = 160 microns

2. in a telescope,, to get larger magnification

fo must bs as alarge as possible and fe must be as small as positive

so 30cm must be objective

b. image will be viutual and erect and magnified

c,. L = 30 +3 = 33 cm

they arearranged so to increase the magnyfying power

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.