The direction of induced current may also be found by lenz's law which was formulated by Lenz in 1835.this law state that, in effect, that electromagnetically induced current always flows in such a direction that the direction of the magnetic field set up by it tends to oppose the vary cause which produced it.
lenz's law can be explaining with the help of the beloved fig.
It consist of a bar magnet, iron core coil and galvanometer which connected across the coil, the vary cause in this case is the motion of the magnet motion. There are two type of motion.
- Approaching motion
- With drawn motion
By applying approaching the magnet to wards the coil the left side of the coil becomes north pole and we know that similar pole repel each other, by withdrawn the magnetic from the coil side, south pole is formed on the left side of the coil and we know that dissimilar pole attract each other.
So in first case approaching of the magnet was vary cause which was opposite by the repulsion of the magnetic field of the coil and in the second case withdrawn of the magnet was vary cause for the induced current which was oppose due to the magnetic field of the coil.