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Optical Instruments — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsOptical Instruments1 Mark
Question
 A man is looking at a small object placed at his near point. Without altering the position of his eye or the object, he puts a simple microscope of magnifying power 5X before his eyes. The angular magnification achieved is:
  1. 5
  2. 2.5
  3. 1
  4. 0.2
✓

Answer

  1. 1
Explanation:

We have,

h = Object height

u = Object distance = 25cm

D = Near point = 25cm

Now,

$\text{m}=\frac{\frac{\text{h}}{\text{u}}}{\frac{\text{h}}{\text{D}}}$
$\Rightarrow\text{m}=\frac{\frac{\text{h}}{25}}{\frac{\text{h}}{25}}$
$\Rightarrow \text{m}=1$

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