An electromagnet is the most powerful type of magnet there is. It is a magnet with a current running through it that can be turned on and off .Why might it be useful to be able to turn the electromagnet on and off? to control the strength of the magnet

to reduce wearing out of the magnet over time

to latch onto and let go of objects

to not waste electricity

Iwould you figure it out but you don't have a picture or in your question as to what the physical property you're looking for is

Firstly, the water in the dams hold gravitational potential energy as they are above ground level. the gravitational potential energy is then transferred to kinetic energy as it falls, spinning the turbinethe turbine then spins the generator, which is a large magnet surrounded by metal coils. by doing this, the generator generates electricity. in this action, the energy transfer taken place is kinetic to electric energy

The answer is 3.