Question

In a generator, an external force moves a magnet. The external force does work and this work is converted into electrical energy.

S C FFM N

• Refer to the image on the right. Describe how this simple model for the generators in a hydroelectric plant works.
• Imagine you were actually turning the magnet by hand to generate a current. Neglecting friction, would you have to do work to keep the wheel turning?

Answer 1

In the given image there are 1. water tap (wheel) Coel of Conductor with the bult following components magnet attached to the turbine 21 hence Here to generate current we will consider basic principle that changing magnetic flux through conductor will enduce an emf in that conductor and Current will flow through that Conductor. nie ent induced do dt where & is emf induced N is number of turns of coil 4. & is magnetic flux through the coil 4 o I BA where B is magnetic held and of coil. E-N de area Now working when tap is open water will fall on the wheel so potential energy of water will be use to rotate the wheel

and as wheel starts rotating then magnet attached to it will also rotate which will cause the magnetic field through the coil to change continuously and periodically and that changing magnetic field will lead to changing magnetic flux which will induce in that coll and due to which to ohms law Current will induce in & bullo process hydroelectric plant will work an emf according that coil bull glows. so by this Yes we have to keep turning the wheel because induced current in the coil will generate its owon magnetic field which will interact with the magnets magnetic field and resist the motion of wheel so we have to keep turning the wheel. hence