Assertion `:` Although the surfaces of a goggle lens are curved, it does not have any power.
Reason`:` In case of goggles, both the curved surfaces have equal radii of curvature.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If assertion and reason both are false.

Answer

A

Explanation

The focal length of a lens is given by
`(1)/(f)=(mu-1)((1)/(R_(1))-(1)/(R_(2)))`
For, goggle, `R_(1)=R_(2)`
`:. (1)/(f)=(mu-1)((1)/(R_(1))-(1)/(R_(2)))=0`
Therefore, `P=(1)/(f)=0`