What happens to an electron in the electric field

In summary, the electron gains kinetic energy as it is accelerated in an electric field and it will lose potential energy as it moves towards the positive plate.
  • #1
hikarigenzo
6
0
Hi,im new here. Can you explain to me what happens to the kinetic energy of an electron when it is accelerated in a uniform electric field? My guess is it will go to the positive plate and loses kinetic energy because it isdoing work against the field. Can anyone clarify this?

Thanks
 
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  • #2
Firstly, welcome.

Why do you think that it is doing work against the field? Negative charge moving up potential is a decrease in potential energy, i.e. work is done to the electron as it is gaining kinetic energy.
 
  • #3
I think maybe my basic is not strong enough. Correct me if I am wrong. The electric field direction is from positive to negative right? So the electron need to do work to go to the positive plate. Am i right?
 
  • #4
No, electrons are negatively charged and are attracted to the positive plate. The direction the arrows in the field point in many pictures is meaningless. It could easily be the other way around and it would change nothing. It's simply that like charges repel and opposite charges attract.
 
  • #5
hikarigenzo said:
I think maybe my basic is not strong enough. Correct me if I am wrong. The electric field direction is from positive to negative right? So the electron need to do work to go to the positive plate. Am i right?

Well, not really. You may work more on the defining formulae. The formulae for field strenth is F=qE. The negativity of q would mean that F would be positive alone the negative direction of E
 
  • #6
Thanks for all the replies, so what happens to the kinetic energy and potential energy of it?
 
  • #7
hikarigenzo said:
Thanks for all the replies, so what happens to the kinetic energy and potential energy of it?

Electrostatic potential decreases of course. Since there is no other force acting on the electron, all these potentials lost to kinetic. Actually, you mentioned accelerated in OP, so what's confusing?
 
  • #8
I have to oversimplify, get a physical picture in myhead and then build up to the mathematical explanation. I think in pictures and envy folks whose mind jumps immediately to the formula.

If i correctly recall a physics class problem from forty++ years ago,
However many volts are across the plates responsible for the field, as it approaches the positive plate the electron's kinetic energy approaches that many electron-volts ..

here's a practical example that even I could follow.

http://wps.aw.com/wps/media/objects/877/898586/topics/topic07.pdf

old jim
 

FAQ: What happens to an electron in the electric field

What happens to an electron in the electric field?

When an electron enters an electric field, it will experience a force due to the electric field. This force will cause the electron to accelerate in the direction of the electric field.

What is the direction of the force on an electron in an electric field?

The force on an electron in an electric field is always in the direction opposite to the direction of the electric field. This is because the electron has a negative charge and will be repelled by the negative charges in the electric field.

How does the strength of the electric field affect the motion of an electron?

The strength of the electric field directly affects the acceleration of the electron. The stronger the electric field, the greater the force on the electron and the faster it will accelerate.

Can an electron ever stop moving in an electric field?

No, an electron will continue to accelerate as long as it is in an electric field. However, the acceleration may decrease if the strength of the electric field decreases or if the electron encounters other forces.

What happens to the speed of an electron in an electric field?

The speed of an electron will increase as it accelerates in an electric field. However, the speed will eventually reach a maximum value, known as the terminal velocity, as the forces on the electron become balanced.

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