C

Cathode Ray Tube

½mv² = eV
Quick Reference
Formula / Notation½mv² = eV
Also Known AsCRT, Braun tube, electron beam tube, cathode ray oscilloscope tube

What is Cathode Ray Tube?

A cathode ray tube (CRT) is an evacuated glass tube in which electrons (cathode rays) emitted from a heated cathode are accelerated by an electric field and deflected by electric or magnetic fields. J.J. Thomson used CRTs to discover the electron in 1897. CRTs were used in oscilloscopes, early television sets, and computer monitors.

Formula & Notation

½mv² = eV

Other Names / Synonyms: CRT, Braun tube, electron beam tube, cathode ray oscilloscope tube

Properties & Characteristics

A cathode ray tube is an evacuated glass tube in which electrons (cathode rays) are emitted from a heated cathode, accelerated by a high voltage, and focused into a beam that strikes a fluorescent screen. Discovered and characterised by J.J. Thomson, who used magnetic and electric deflection to measure the electron's charge-to-mass ratio (e/m = 1.76 × 10¹¹ C/kg). CRTs confirmed the existence and properties of electrons.

Uses & Applications

CRTs were used as display devices in televisions and computer monitors until replaced by flat-panel displays. Cathode ray tubes remain important in oscilloscopes for waveform measurement. The CRT principle is the basis of electron microscopes and X-ray tubes.

Safety Information

CRTs operate at high voltages (10–30 kV) and contain lead glass to absorb X-rays produced by electron beam impact. Implosion hazard if the vacuum envelope is broken. Disposal requires handling as hazardous electronic waste due to lead content.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Cathode Ray Tube
Formula ½mv² = eV
Synonyms CRT, Braun tube, electron beam tube, cathode ray oscilloscope tube

Frequently Asked Questions

A cathode ray tube (CRT) is an evacuated glass tube in which electrons (cathode rays) emitted from a heated cathode are accelerated by an electric field and deflected by electric or magnetic fields. J.J. Thomson used CRTs to discover the electron in 1897. CRTs were used in oscilloscopes, early television sets, and computer monitors.

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