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How are the electrons produced in a cathode ray oscilloscope?

Correct answer: A. By heating a metal filament

  • A. By heating a metal filament
  • B. By ionisation of the air
  • C. By applying an electric field
  • D. None of these

Explanation

Electrons are produced in a cathode ray oscilloscope (CRO) by heating a metal filament through a process called thermionic emission. When the filament is heated to a high temperature, typically using a low-voltage electrical current, the electrons within the metal gain enough thermal energy to overcome the binding forces of the metal lattice and escape into the surrounding space. These emitted electrons form a cloud around the filament and constitute what is known as a thermionic emission.

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About Electromagnetism

Magnetic flux density and magnetic flux describe the strength of a magnetic field and the field passing through a surface. A charged particle moving through a magnetic field experiences a force perpendicular to its velocity and may follow circular or helical motion, depending on the angle between velocity and field.

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