Answer:
(a) 0.34 cm
(b) 1.32 cm
Explanation:
Given that, [tex]m_{o}=-50 [/tex]
[tex]m_{e}=20 cm[/tex]
And the length of objective lens in a microscope
[tex]L=17 [/tex]
And we have d of the eyepiece is 25 cm.
(a) Focal length of the objective is,
[tex]f_{o}=-\frac{L}{m_{o} }\\ f_{o}=-\frac{17}{-50} \\f_{o}=0.34 cm[/tex]
Therefore, objective lens's focal length is 0.34 cm.
(b) Focal length of an eyepiece,
[tex]m_{e}=(1+\frac{d}{f_{e} })\\ 20=(1+\frac{25}{f_{e} }\\ f_{e}=\frac{25}{19}cm\\ f_{e}=1.32cm[/tex]
Therefore, eyepiece's focal length is 1.32 cm.
