NEET2007PhysicsRay OpticsActual
Assertion : Goggles have zero power. Reason : Radius of curvature of both sides of lens is same
Options
- AIf both assertion and reason are true and reason is the correct explanation of assertion
- BIf both assertion and reason are true but reason is not the correct explanation of assertion
- CIf assertion is true but reason is false
- DIf both assertion and reason are false.
Correct answer
A. If both assertion and reason are true and reason is the correct explanation of assertion
Step-by-step solution
The focal length is given by ( 1 f =( -1) ( 1 R₁ - 1 R₂ ) ). For goggle lenses, both sides are curved the same way. (R₁ ) and (R₂ ) are positive. If they are the same, ( 1 f =0 ) i.e. power is zero.