Electromagnetism
We will place compass needle near
these three iron bar. The compass needle will show response near magnet.
So
when we take compass needle near the iron bar and if this compass needle did to
change it s direction then this means that this iron bar is not a magnet. You
will move the bar magnet into and out of the coil and this changing magnetic
field will induce emf and electric current. An electric motor is a device that
converts electric energy into mechanical energy. It is according to the law of
electromagnetic induction Len’s law. States that the direction of the induced
e.m.f is always such as to oppose the change producing it. There fore coil will
swing relative to the magnet. When we place a conductor wire in a magnetic
field then it will experience a magnetic Force in the direction perpendicular
to the magnetic field. To generate the maximum voltage (emf)
in the conductor
we must move the wire in such a way that angle between velocity or wire and
magnetic field must bc 900 . A motor is an electromagnetic device
that coverts electrical energy into mechanical energy. So we supply electricity
to it will give us mechanical energy as the output. A generator is just
opposite it converts mechanical energy to electrical energy. We provide the
mechanical energy (like a turbine or any other prime mover) it will give us
electrical energy. To reverse the direction of current, the connection to coil
is made through an arrangement of brushes and a ring that split into halves, called
a split ring. Commutator the split ring is arranged so that each half of the commentator
changes brushes just as the coil reaches
the vertical position, changing brushes reverse the current in the loop.
No, a transformer connote operate on
direct current. The primary coil has to induce. The coil has to induce current
in the secondary coil. The only way this can happen is if there is a varying magnetic field in the primary which will then induce a varying magnetic filed
in secondary which result current in the secondary coil.
No comments:
Post a Comment