Name the gases produced on passing electricity through water.

The heat produced by passing an electric current through a fixed resistor is proportional to the square of:

Write an expression for the heat produced when an electric current is passed through it.

Classify the following as chemical or physical changes : ** cutting of trees. ** melting of butter in a pan, ** rusting of almirah, ** boiling of water to form steam, ** passing of electric current, through water and the water breaking down into hydrogen and oxygen gases. ** dissolving common salt in water, ** making a fruit salad with raw fruits, and ** burning of paper and wood.

Name two effect produced by electric current.