An objective with semi-aperture angle is first used in air and then with immersion…

PHYSICS · Single correct · CBSE · Physics · Ray Optics and Optical Instruments · Ray Optics and Optical Instruments

Problem

An objective with semi-aperture angle

\alpha

is first used in air

(n=1)

and then with immersion oil of refractive index

1.5

, keeping

\alpha

unchanged. How does the minimum resolvable distance change? (a) It remains the same. (b) It becomes

1.5

times the previous value (resolution worsens). (c) It becomes

\dfrac{1}{1.5}

times the previous value (resolution improves). (d) It becomes

2.25

times the previous value.