Flashcards
9.4 From Ideas to Implementation
Cards in this deck (13)
- 1wave theory of cathode raysmistakenly showed that cathode rays couldn't be deflected by electric plates
rays could cast shadows and be diffracted as well as cause fluorescence - 2particle theory for cathode raysrays could charge objects negatively through interaction
able to carry and transfer momentum - 3Thomson's experimentshowed that cathode rays were deflected by electric fields as well as magnetic fields by adding a magnetic field to a CRT so that the ray would pass through undetected. he equated the electric and magnetic forces (qE = qvB) to calculate the charge to mass ratio for an electron
- 4electron gun in CROmaking the grid more positive or negative controls the number of electrons reaching the anodes
control the intensity of the cathode ray and the brightness of the display - 5deflection system in CROmanipulates cathode ray so useful information can be displayed
consist of Y plates (horizontal, control vertical deflections) and X plates (vertical, control horizontal deflections) - 6display screen of CROwhen a beam of cathode rays strike a pixel, it glows, allowing information to be displayed
displays signal as a voltage-time graph
calculates amplitude & period of the wave - 7electron gun in TV setred, green and blue guns
the grid in each electron gun controls the brightness of the display. the grid and turning on/off time of a particular gun is controlled by amplified electric signals captured by an antenna receiving signals from a TV station - 8deflection system in TV setsupplied by electromagnets
allow beams to be deflected through greater angles so the tube can be shorter. - 9display screen of TVeach electron gun is focused to hit a phosphor on the tube at various intensities, determining the colour at a spot on the screen
- 10collimated crookes tubemagnetic field used to deflect the beam, showing the ray is charged
- 11maltese cross tubecathode rays have low penetrating power, travel in straight lines, particles not waves
- 12paddle-wheel tubehave mass and momentum
- 13electric platesnegatively charged
Information
- Description
- Flashcards on 9.4 From Ideas to Implementation, created by Grace Easton on 13/07/2017.
- Created by
- Grace Easton
- Views
- 10
- Tags
- Rating