2017 · Q43
Which one of the following statements is not correct ?
General KnowledgePhysics
- AThe cathode rays originate from cathode and proceed towards the anode in a cathode-ray discharge tube.
- BThe television picture tubes are nothing but cathode-ray tubes.
- CThe cathode rays themselves are not visible.
- DThe characteristics of cathode rays depend upon the nature of the gas present in the cathode-ray tube.
Explanation
Cathode rays are streams of electrons whose charge-to-mass ratio is independent of the cathode material and the gas in the tube — that universality proved they are a fundamental particle. So D is the incorrect statement; A, B, and C are correct (they travel cathode-to-anode, old TV picture tubes were CRTs, and the rays themselves are invisible). Hence C.