Question

Why do oil immersion objectives have higher numerical apertures than dry (non-oil)

lenses?

a. They are used closer to the specimen, therefore their lenses intercept light at

angles dray lenses would miss.

b. The oil used with the lenses prevents light from being refracted away from the

objectives as does occur with the dry lenses.

c. The oil used with the lenses increases the difference between the refractive

indices of the slide and the medium between the slide and the objective lens.

d. A and B

e. B and C​

Answer 1

Answer:

If the Space between the objective lens and the specimen is filled with oil however the numerical aperture can obtain values greater than 1 . This is because of oil has refractive index >1.

Explanation:

Answer 2

they are used closer to the specimen