Which effect of electric current is utilized when a thin layer of chromium metal is deposited on an iron tap? What is this process known as?

Does pure water conduct electricity? If not, what can we do to make it conducting?

In case of a fire, before the firemen use the water hoses to throw water to douse fire, they shut off the electricity supply for the area. Explain why this is done.

For electroplating copper on an iron object, which terminal of the battery (positive or negative) is connected to the iron object? Also name the electrolyte you will use for this purpose.

What is meant by the chemical effect of electric current? Explain with the help of an example.