The KE of an electron accelerated by an electric field

In summary, when an electron is accelerated through a PD of V volts, its kinetic energy will be equal to eV. However, some of the energy from the field is also used to generate electromagnetic waves and build a magnetic field, resulting in a longer journey for the electron and a total energy consumption of V x I x Time.
  • #1
claudius
1
0
Hello,

An electron accelerated through a pd of V volts will have a K.E = eV. Why isn't the K.E less than this considering that some of the work done by the field has been radiated as electromagnetic waves by the accelerating electron ?

All insights very welcome.
 
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  • #2
claudius said:
Hello,

An electron accelerated through a pd of V volts will have a K.E = eV. Why isn't the K.E less than this considering that some of the work done by the field has been radiated as electromagnetic waves by the accelerating electron ?

All insights very welcome.
The generator will do work in accelerating the electron, because a current is flowing, and must supply energy not only to KE but also to radiation and building a magnetic field. This means the electron takes longer for its journey than for KE only. Power is V x I but total energy is V x I x Time.
 

1. What is the formula for calculating the KE of an electron accelerated by an electric field?

The formula for calculating the KE (kinetic energy) of an electron accelerated by an electric field is KE = 1/2 * m * v^2, where m is the mass of the electron and v is its velocity.

2. How does an electric field accelerate an electron?

An electric field exerts a force on an electron, causing it to accelerate in the direction of the field. The strength of the field and the charge of the electron determine the magnitude of the force.

3. Can an electron's KE be negative?

No, an electron's KE cannot be negative. KE is a measure of the energy an object has due to its motion, and since an electron is always moving, it will always have a positive KE value.

4. How does the KE of an electron change as it moves through an electric field?

As an electron moves through an electric field, its KE will increase due to the work being done by the field on the electron. The increase in KE will depend on the strength of the field and the distance the electron travels through it.

5. What factors can affect the KE of an electron accelerated by an electric field?

The KE of an electron accelerated by an electric field can be affected by the strength of the electric field, the charge of the electron, the mass of the electron, and the distance the electron travels through the field.

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