Question

Assertion: Refractive index of free space (air or vacuum) is maximum.

Reason: Glass is optically denser than both air and water.

Options

• If both Assertion and Reason are true and the Reason is correct explanation of the Assertion.

• If both Assertion and Reason are true, but Reason is not correct explanation of the Assertion.

• If Assertion is true, but the Reason is false.

• If Assertion is false, but the Reason is true.

Answer 1

If Assertion is false, but the Reason is true.

Explanation: 

The refractive index of free space/vacuum is 1.0, which is the absolute minimum possible refractive index, making the assertion false. Glass ($$\mu \approx 1.5$$) is optically denser than both air ($$\mu \approx 1.0$$) and water ($$\mu \approx 1.33$$), so the reason is true.