When the free ends of a tester are dipped into a solution, the magnetic needle shows deflection. Can you explain the reason?

When the free ends of a tester are immersed in a solution and the magnetic needle exhibits deflection, it signals the presence of an electric current within the solution. This occurrence indicates the solution’s capacity to conduct electricity.

The deflection of the magnetic needle is an indicator of the flow of electric current passing through the solution. Such conductivity is typically facilitated by substances or compounds within the solution that can dissociate into charged particles known as ions when dissolved in a solvent like water.

Here’s how this unfolds:

1. Ion Dissociation: Certain substances, upon dissolving in a solvent, disintegrate into ions, which are charged particles. These ions possess the ability to move freely within the solution.

2. Conductivity via Ions: When the tester’s ends make contact with the solution, it forms a complete electrical circuit through the solution. If the solution harbors ions capable of conducting electricity, these ions permit the flow of electric current through the solution.

3. Magnetic Needle Deflection: The flow of electric current generates a magnetic field encircling the path through which the current moves. This magnetic field interacts with the magnetic needle of the tester, causing its deflection.

Therefore, the deflection of the magnetic needle serves as an indication that the solution conducts electricity due to the presence of ions or substances capable of dissociating into ions, thereby facilitating the flow of electric current through the solution.