Water is not suitable for extinguishing fires involving electrical equipment oil and petrol. why?

Water is a natural conductor of electricity and if you throw water on an electrical fire, you can get shocked or electrocuted. Also, water may enable to fire to spread by conducting electricity throughout the room and potentially igniting flammable materials.

Also, water and oil do not mix. Pouring water can cause the oil to splash and spread the fire. This is just plain dangerous for a great number of obvious reasons.