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15. Electromagnetism eLearn.Punjab
If we apply the law of conservation of energy to electromagnetic Direction of induced current
induction, we realize that the electrical energy induced in a conductor
comes from the kinetic energy of the moving magnet. We do some Fig 15.15 (a): Direction of induced
work on the magnet to bring it close to the solenoid. This work current when magnet is moved
consequently appears as electrical energy in the conductor. Thus towards the coil
mechanical energy of our hand used to push the magnet towards or
away from the coil results into electrical energy. Hence, Lenz’s law is
a manifestation of the law of conservation of energy.
Animation 15.9 : Magnet Electricity Fig 15.15 (b): Direction of induced
Source & Credit : Jacksonsciencealive current when magnet is moved
away from the coil
15.7 A.C. GENERATOR
If a coil is rotated in a magnetic field, a current will
be induced in the coil. The strength of this induced Do you know?
current depends upon the number of magnetic lines
of force passing through the coil. The number of lines
of magnetic force passing through the coil will be
maximum when the plane of the coil is perpendicular
to the lines of magnetic force. The number of lines of
magnetic force will be zero when plane of the coil is
parallel to the lines of force.
A generator inside a hydroelectric dam uses
electromagnetic induction to convert mechanical
energy of a spinning turbine into electrical energy.
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