The energy transformations that occur is Mechanical → electrical → light.
Explanation:
When the water falls through the dam the gravitational potential energy of water is transformed into kinetic energy.
This energy rotates the turbine (mechanical energy) connected to a generator.
Now this mechanical energy is converted into electrical form through the process of electromagnetic induction (when a conductor cuts the magnetic field, electricity is produced).
The electricity thus produced is driven to different offices and houses through wires.
By drawing this current we light our homes and offices.
