Question

In a CRT, the acceleration of an electron is controlled by changing ____________ between the cathode and anode.
A) Potential difference
B) Space
C) Temperature
D) None of those

Answer 1

A cathode electrode in a vacuum tube system is a metal surface that emits electrons into the evacuated space of the tube. The cathode is heated to a temperature that causes electrons to be liberated of its surface into the evacuated space in the tube, a process called thermionic emission.

Complete step by step answer:
A cathode ray tube (CRT) is a special type of vacuum tube in which images are produced when an electron beam strikes a phosphorescent surface. We have to create an image by using modulates, accelerates, and deflects electron beam(s) onto the screen. Most of the desktop computer displays make use of CRT for image displaying purposes.
The cathode-ray tube (CRT) is a vacuum tube that consists of one or more electron guns and a phosphorescent screen, and is used to display images. It modulates, accelerates, and deflects electron beams onto the screen to produce the images.
Positive potential is given to anode and a negative potential is given to the cathode. Because of this potential difference, electrons generated by the heating cathode are attracted to the anode due to this potential difference. If zero potential difference is applied between anode and cathode in CRT, no electron would strike the screen. It is because of this potential difference between anode and cathode that the whole process occurs.
After the electrons are emitted from the cathode, they come under the influence of an electrical force pulling them toward the anode. In velocity and kinetic energy causing an increase because the force accelerates. This increase in kinetic energy continues as the electrons travel from the cathode to the anode.

The correct option is A

Note: The CRT consists of three main components: the electron gun, the electron beam deflector, and the screen and phosphors.
The full name of CRT is "Cathode Ray Tube." CRT is the technology used in traditional computer monitors and televisions. The image on a CRT display is produced by firing electrons from the back of the tube to phosphors located towards the front of the display.