Question

Which of the following can travel through vacuum?

• A. Light waves
• B. Heat waves
• C. $X$-rays
• D. Sound waves

Answer 1

Answer: (A), (B), (C)

The correct options are
A Light waves
B Heat waves
C $X$-rays

Heat rays are infra-red rays.

Light rays, infra-red rays and X-rays are all electromagnetic rays.

Electromagnetic rays can travel through vacuum and through transperent media.

However, sound waves are mechanical longitudinal waves. They need a material medium for travelling. They can't travel through vacuum.