2
$\begingroup$

We know that two wires carrying current in the same direction attract each other and there is a well know explanation for that. I am just curious to know if anyone has ever seen any experiment where two cathode rays actually attract each other.

$\endgroup$
1
  • $\begingroup$ Nobody ever measured this. $\endgroup$ Jun 12, 2022 at 3:14

2 Answers 2

1
$\begingroup$

The electrostatic repulsive force between two beams of electrons is always greater than the magnetic attractive force between the moving electrons.
The proof of this is to be found here.

When the electrons are moving in a wire the net electrostatic repulsive force is zero because the net charge on a wire is zero and so only the attractive magnetic field force is felt by the wires.

$\endgroup$
0
$\begingroup$

Two cathode rays do not necessarily attract each other. This can be observed from electron beam experiments. We can assume that an electron beam is made up of several electron rays. The beam always diverges due to space charge effects and reaches a limiting value.

$\endgroup$
4
  • $\begingroup$ Cathode rays can be considered as current in opposite direction,,so what is the difference between the current carrying wire and this cathode ray? $\endgroup$
    – positron
    Apr 22, 2017 at 7:58
  • $\begingroup$ @Mamun give me some time to do the calculations :) $\endgroup$ Apr 22, 2017 at 8:12
  • $\begingroup$ @Mamun The flow of current in a conductor and the flow of electrons in cathode rays are different phenomena. In a conductor the electrons flow through a tightly packed lattice. In a conductor I can define a 'current' that will produce magnetic field around a conductor. But when left loose in the form of cathode rays the space charge effect dominates and coulumb repulsion overtakes causing the diverging beam $\endgroup$ Apr 22, 2017 at 8:21
  • $\begingroup$ yeah i got it😀 $\endgroup$
    – positron
    Apr 22, 2017 at 8:22

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.