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Q26 (NDA-II/2019) Science & Technology › Basic Science (Physics, Chemistry, Biology) › Atomic and nuclear physics

Which one of the following statements regarding cathode rays is not correct?

Result
Your answer: —  Â·  Correct: B
Explanation

Cathode rays are streams of electrons emitted from the cathode, which is the negative electrode in a vacuum tube. These rays originate at the cathode and move toward the anode (the positive electrode) because electrons are negatively charged and are attracted to the positive potential. Therefore, the statement that they start from the anode and move towards the cathode is incorrect. In the absence of external electric or magnetic fields, cathode rays travel in straight lines. They can be deflected by such fields, a property used to calculate the electron's charge-to-mass ratio. Furthermore, television picture tubes are a common application of cathode ray tubes (CRTs), where an electron beam is directed at a phosphor screen to create visual images [1].

Sources

  1. [1] https://www.sciencedirect.com/topics/physics-and-astronomy/cathode-ray-tube
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