Introduction to sound waves

Q.

In which gas is the speed of sound is maximum? What is its value?

Q. Assertion :Two persons on the surface of moon cannot talk to each other Reason: There is no atmosphere

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q. The velocity of sound in vacuum is

1. $330m{s}^{-1}$
2. Zero
3. $332m{s}^{-1}$
4. $228m{s}^{-1}$