Q. In a discharge tube ionization of enclosed gas is produced due to collisions between :
A) positive ions and neutral atoms/molecules
B) negative electrons and neutral atoms/molecules
C) photons and neutral atoms/molecules
D) neutral gas atoms/molecules
Explanation
[Solution from source] In a discharge tube the strong electric field accelerates the free electrons, which knock electrons off neutral gas atoms or molecules and ionise them. Positive ions are heavy and gain much less speed between collisions, so they are not the main cause of ionisation. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.