Moderate

When the filament in a cathode rays oscilloscope (CRO) is heated, then the emitted particles are

Correct answer: B. neutrons

  • A. protons
  • B. neutrons
  • C. electrons
  • D. positrons

Explanation

When the filament in a cathode rays oscilloscope (CRO) is heated, it releases electrons. These electrons are then accelerated towards the screen of the CRO, where they form a beam of cathode rays. Neutrons are neutral particles found in the nucleus of an atom and are not emitted in a CRO. Protons are positively charged particles in the nucleus, and positrons are positively charged antimatter particles, neither of which are emitted in a CRO. Therefore, the correct answer is 'neutrons'.

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About Quantum Theory and Radiation

Quantum theory treats electromagnetic radiation as packets of energy called photons, with energy proportional to frequency through E equals hf. The topic covers Planck's hypothesis, photon momentum, the photoelectric effect, threshold frequency, work function and wave particle duality, distinguishing quantised energy exchange from classical continuous radiation.

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