Q. Which of the following statements regarding the speed of light in various media is/are correct?

1. It is greater in vacuum in comparison to glass.
2. It is greater in hot glass in comparison to cold glass.

Select the correct option from the codes given below:
Answer: Both 1 & 2 are correct
Notes: Speed of light is maximum in vacuum and decreases in denser media like glass due to higher refractive index. Heating glass reduces its density, thus lowering the refractive index and increasing the speed of light. Therefore, both statements are correct: speed is greater in vacuum than in glass, and in hot glass than cold glass.