What is the primary function of the cathode ray tube (CRT) in an oscilloscope?

Explanation:

Primary Function of the Cathode Ray Tube (CRT) in an Oscilloscope

A Cathode Ray Tube (CRT) is a vacuum tube containing one or more electron guns (cathodes) and a phosphorescent screen used to display images. It modulates, accelerates, and deflects electron beams onto the screen to create visual representations of electrical signals. CRTs were commonly used in oscilloscopes, television sets, computer monitors, and radar displays before the advent of modern display technologies.

Working Principle: In an oscilloscope, the CRT is used to display waveforms of electrical signals. The primary function of the CRT in an oscilloscope is to visually represent the voltage of an electrical signal over time. Here's how it works:

• Electron Gun: The CRT contains one or more electron guns that produce a stream of electrons (cathode rays). These electrons are emitted by a heated cathode and accelerated through an anode.
• Deflection System: The electron beam is then directed by a deflection system, which can be either electrostatic or magnetic. In oscilloscopes, electrostatic deflection is commonly used. Two pairs of deflection plates are positioned inside the CRT: one pair for vertical deflection (Y-axis) and another for horizontal deflection (X-axis).
• Phosphorescent Screen: The electron beam strikes the phosphorescent screen, causing it to glow at the point of impact. The intensity of the glow is proportional to the number of electrons striking the screen. By controlling the deflection of the electron beam, the oscilloscope can draw the waveform of the input signal on the screen..