Question

Define the following terms.
(a) Refractive index
(b) Power of a lens​

Answer 1

Answer:

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Explanation:

a). The refractive index (also known as refraction index or index of refraction) of a material is a dimensionless number that describes how fast light travels through the material.

b). If a lens has a shorter focal length it is said to be more powerful. The power of a lens is defined as the reciprocal of the focal length.