Question

In case of a fire, before the firemen use the water hoses, they shut off the main electrical supply for the area. Explain why they do this.

Answer 1

Conduction through water:

1. The water present in a water hose contains salts.
2. We know that salts are an excellent conductor of electricity.
3. This is because salts in water form ions.
4. Ions are very good conductors of electricity.
5. Therefore, if the electrical supply of that area of kept open before water is sprayed, an electric current will be conducted through the water.
6. This can cause injury to the firemen.
7. Hence, the main electrical supply for the area is shut off before the firemen use the water hose.