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.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
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.
Practise Electromagnetism
1,176 free Electromagnetism MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Physics questions like this
Physics is on 16 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Electromagnetism questions
What is emitted by the hot metal filament in a cathode ray oscilloscope?
The cathode ray oscilloscope is useful for:
By means of waveform displayed on the screen of CRO, we can measure:
The function of grid in cathode ray oscilloscope is:
The electron gun in cathode ray oscilloscope consists of:
The current passing through the coil of galvanometers is directly proportional to: