help please (1 Viewer)

[Arithela]

1. Account for the need for high voltages and low gas pressures in cathode ray tubes.
2. Contrast the particle movements in a cathode ray tube containing sodium vapour at low and very low pressures.
3. Propose arguments in support of the view that cathode rays were high velocity particles.


for question 1, does the high voltage allow cathode rays to flow from the cathode to anode and completes the circuit. low gas pressures allow the electrons to accelerate to high speeds to the anode therefore minimising particle collisions and hence less striations appear in the tube?

thanks!

 

[Forbidden.]

It's probably because a high potential difference in the system gives the electrons greater potential energy which gets converted to kinetic energy while in motion.

 

[Arowana21]

1. High voltages: needed to liberate enough electrons, to cause a current
Low gas pressure is the type of environment in which electrons can freely move
2. Not sure about the sodium part, but in a cathode ray tube, the electrons would move towards the positive plate (vertical direction) but since the velocity is in horizontal direction, with both directions interacting the overall path of the electron is a parabolic path.
3. I am not to sure, but i think u can manage if u do some research...lol

as for the last comment u made, yes u are correct

 

[vds700]

isn't the high voltage needed to create a strong enough electric field to attract electrons out of the cathode to the anode (E = V/d)...thats my understanding of it. And low gas pressures is required to minimise collisions of electons with gas molecules, i think, so they can reach the anode.

 

[Arowana21]

Technically, the electrons WOULD move in the direction of the current made, and yes you right about low pressure in reducing collisions.
What i was also referring to is the movement of electrons with electric plates affecting its movement

 

[margaret-lise]

is this for physics detailed study further electronics?

 

[Arowana21]

THIS IS PHYSIC, if u havent noticed, this comes under cathode ray tubes ffs