A typical red blood cell subtends an angle of only 1.5times10-5rad when viewed a

Question

A typical red blood cell subtends an angle of only 1.5times10-5rad when viewed at a person's near-point distance of 25 cm. Suppose a red blood cell is examined with a compound microscope in which the objective and eyepiece are separated by a distance of 13.0cm . Given that the focal length of the eyepiece is 2.5cm , and the focal length of the objective is 0.42cm , find the magnitude of the angle subtended by the red blood cell when viewed through this microscope. Express your answer using two significant figures.

Explanation / Answer

The angular seperation of the RBC viewed at the nearer point is = 1.5*10-5 rad
Focal length of the objective fo = 0.42 cm
Focal length of the eye piece is fe = 2.5 cm
Seperation of objective and eye piece is d = 13 cm
The angular magnification of the microscope is given by
M = -(d-fe )/(fofe) (25 cm)
M = -{(13 cm - 2.5 cm)/(0.42 cm*2.5 cm)}* (25 cm)
M = -250
negative sign indicates that the imege is inverted
Therefore
the angular seperation RBC as viewed from the microscope is
' = M
' = 250*1.5*10-5 rad
' = 3.75*10-3 rad

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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