#

The demonstration for module 6.1, of a circular loop in time-varying magnetic field shows a current induced in a loop in response to the change in magnetic flux flowing through it.

The demonstration on the top left shows, a circular wire loop is connected to a resistor R sub L in series with an ammeter. An outward magnetic field B produces a current I in counterclockwise direction.

The demonstration on the bottom left shows, a graph of current and magnetic field with respect to the time. A sinusoidal wave of one cycle depicts the curve of I and a co-sinusoidal wave of one cycle depicts the curve of magnetic field, B. The curve of current starts from the origin, whereas the curve for magnetic field starts from positive vertical axis.

A text on the left reads demonstration of Faraday’s law.

The circular wire loop shown in the figure is connected to a simple circuit composed of a resistor R sub l in series with a current meter. The time-varying magnetic flux linking the surface of the loop induces a V sub EMF, and hence a current through R. The purpose of this demo is to illustrate in the form of a slow motion video, how the current I varies with time. In both magnitude and direction, when B of t equals B sub 0 Cos omega t.

Note that I of t is a maximum when the slope of B of t is a maximum, which occurs when B itself is zero. The direction of I of t is dictated by Len’s law.