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Which one of the following statements is not true for cathode rays?

1. Cathode rays produce heat when incident on metals
2. Cathode rays travel in a straight line
3. Cathode rays do not deflect in electric field
4. Cathode rays produce fluorescence when they fall on certain materials

Correct answer: Cathode rays do not deflect in electric field

Solution

Cathode rays are streams of electrons, which are negatively charged particles. They are deflected in an electric field due to their charge, making option C incorrect.

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