Question

The focal lengths of the objective and eyepiece of a microscope are 1.25 cm and 5 cm respectively. Find the position of the object relative to the objective in order to obtain an angular magnification of 30 in normal adjustment.

Answer 1

$\huge\rm\underline\purple{Question :-}$

The focal lengths of the objective and eyepiece of a microscope are 1.25 cm and 5 cm respectively. Find the position of the object relative to the objective in order to obtain an angular magnification of 30 in normal adjustment.

$\huge\rm\underline\purple{Answer :-}$

$\green{\underline\bold{Given,}}$

• Focal length of the objective, Fo = 1.25 cm
• Focal length of the eyepiece, Fe = 5 cm
• Magnification,m = 30
• Least distance of the distinct vision,D = 25 cm

$\red{\underline\bold{To\:find,}}$

• The position of the object = ?

$\orange{\underline\bold{We\: know\: that,}}$

m = $\frac{L}{Fo}$(1 + $\frac{D}{Fe}$)

⇒30 = $\frac{L}{1.25}$(1 + $\frac{25}{5}$)

⇒L = $\frac{30×1.25}{6}$

⇒L = 6.25 cm

$\pink{\underline\bold{∴\: The\: required\:answer\:is\: 6.25\: cm}}$

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Answer 2

Answer:

your answer is6.25

hope it help