Define the Working of The Television

This leads to a technology that works to create the picture every time you turn on your television or your computer monitor. This same technology was originally used in cathode ray tubes and later to make oscilloscopes, which are very useful laboratory instruments that can display a calibrated value of a voltage or current as it changes in time.

If we have a beam of electrons traveling in space where there is first a uniform electric field in the up and down direction, and, secondly, a uniform electric field in the side-to-side direction (crossed electric fields), the path of an electron beam traveling through these fields can be controlled by adjusting the electric fields (by changing the voltage applied to the two parallel plate capacitors). The electrons are pulled from the center toward the positive plate of the first capacitor. If the electric field is increased, the electrons are deflected further, and if the electric field is decreased, the electrons are deflected less. If the voltage is applied so that the upper plate is charged negatively, the electrons are deflected downward from the center. The second parallel plate capacitor creates a variable side-to-side electric field allowing for a changeable side-to-side position of the electrons. By changing the applied voltages on the two capacitors and turning the electron beam on or off, the beam of electrons can be made to scan left to right and then top to bottom, in order to light up chosen points on the fluorescent screen in shades of black to white, creating the intended picture.

In an oscilloscope, the first capacitor is connected to the signal you want to measure, so that deflections up and down indicate the size of the signal. The voltage on the second capacitor is varied to repeatedly scan the electron beam from left to right at a constant speed, so that each horizontal division is equal to a given amount of time.