Which of the following types of waves cannot travel through a vacuum?
A
sound waves
B
light waves
C
infra-red waves
D
x-radiation
E
radio waves
Verified Correct Answer: A.
Physical Principles & Numerical Solution
Sound waves are mechanical waves that require a medium (such as air, water, or solids) to propagate.
Light waves, infra-red waves, x-radiation, and radio waves are electromagnetic waves and can travel through a vacuum.
Source: Myschool Past Questions Archive (Record #29167)