Assertion: Goggles have zero power. Reason: Radius of curvature of both sides of lens is same

Question

Assertion: Goggles have zero power. Reason: Radius of curvature of both sides of lens is same (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 both assertion and reason are false

Tardigrade Admin · Accepted Answer

The focal length is given by (1/f)=(μ-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.

Q. Assertion : Goggles have zero power.
Reason: Radius of curvature of both sides of lens is same

If both assertion and reason are true and reason is the correct explanation of assertion

If both assertion and reason are true but reason is not the correct explanation of assertion

If assertion is true but reason is false

If both assertion and reason are false

The focal length is given by
$\frac{1}{f} = (μ - 1) (\frac{1}{R _{1}} - \frac{1}{R _{2}}) .$
For goggle lenses, both sides are curved the same way. $R_{1}$ and $R_{2}$ are positive. If they are the same, $\frac{1}{f} = 0$ i.e. power is zero.

Q. Assertion : Goggles have zero power. Reason: Radius of curvature of both sides of lens is same