How will two parallel beams of electrons behave while moving in the same direction?
A. Repel each other
B. attract each other
C. not interact with each other
D. annihilate each other

Hint: We know that the Coulomb force of attraction or repulsion tells us about the attraction or repulsion between the charges. We all know that both the positive charges attract each other, and both the negative charges repel each other.

Complete step by step answer:
We know that Biot-Savart’s law tells us about the magnetic field produced in proximity to wiring when the current flows in a wire. There is also a magnetic force of attraction linked to the wire, which can attract or repel a conductor placed closed to it.
When the electrons move in two parallel wires, then the magnetic field develops around the wire. The force of attraction due to the magnetic field on two wires is in the same directions to each other hence the beam of the electron will attract each other.
When the electrons move at high speed, the magnetic force of attraction overcomes the electrostatic force of repulsion, and hence the wires will attract each other.
Therefore, two parallel beams of the electron will attract each other, and the correct option is (B).

Additional information:
Suppose an electric current is flowing through the wire, and if we keep a metal needle close to the wire, then the arrow will deflect towards the wire, and hence it is known as the attraction force that is attracting the metal needle.

Note: If two electrons are moving in two straight parallel wires in the same direction but in slow motion, then the force of repulsion due to electrostatic force is overcome by the power of attraction due to magnetic force electrons will repel each other.