Q. The waves which cannot travel in vacuum are:

 2971  212 ManipalManipal 2004Electromagnetic Waves Report Error

Solution:

As X-rays, radio-waves and ultra-violet waves are electromagnetic waves so, they can travel in vacuum as well as in medium. But on the other hand longitudinal waves cannot travel in vacuum. They require medium for its travel. Infrasonic waves are longitudinal waves therefore, they cannot travel in vacuum.