Microscope Resolution Oil Immersion – Rankers Physics

Refraction by Spherical Surfaces: Practice Problem & Solution

Assertion (A): For better resolution, in microscope we prefer "Oil immersed object". Reason (R): Refractive index of oil is closer to the refractive index of objective glass.  
(1) Both (A) & (R) are true and the (R) is the correct explanation of the (A)
(2) Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
(3) (A) is true but (R) is false
(4) Both (A) and (R) are false

Solution Explained:

To solve this problem, we apply the core principles of Refraction by Spherical Surfaces. Understanding the underlying formula is key to arriving at the correct answer below:

Oil immersion is used in microscopes to increase the numerical aperture (NA) and thus improve resolution. Thus, (A) is true.
The refractive index of the immersion oil is chosen to be very close to that of the objective lens glass, which minimizes refraction and maximizes the angle of light collected, increasing NA. Thus, (R) is true and is the correct explanation of (A).

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Similar Practice Questions

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