To examine a particular blood sample in biology lab, a student uses a compound m

Question

To examine a particular blood sample in biology lab, a student uses a compound microscope set to have a magnification of -4505. The objective and eyepiece are both attached to a tube which is 16.5 cm in length and the eyepiece has a focal length of 2.63 cm. The near point of the person using the microscope is 24.5 and you can assume she can view the image produced with a fully relaxed eye.

a) What is the focal length of the objective?
b)What is the distance between the blood sample and the objective lens?

For A I did: -4505= (16.5x24.5)/(2.63 x X) and solved for x which was .0341 cm, but said that was wrong. Pls help. Thanks.

Explanation / Answer

Given Data: Overall magnification, M = -4505 Length of the tube, l = 16.5 cm Focal length of eyepiece, fe = 2.63 cm Near point distance, N = 24.5 cm Solution: a) Focal length of the objective is calculated using the relation                                      M = - N l / fo fe                             - 4505 = - (24.5 cm) (16.5 cm) /fo (2.63 cm)                                      fo = 0.034 cm ------------------------------------------------------------------------------ b) Image distance from the objective is calculated as                              di = l - fe                                   = 16.5 cm - 2.63 cm                                   = 13.87 cm The object distance for the objective lens is calculated using the thin lens equation                                  1/d0 + 1/ di   = 1/  fo                                   1/d0 = 1/ (0.034 cm) - 1/ (13.87 cm)                                      d0 = 0.034 cm

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---